Three-dimensional Ground Reaction Force Symmetry Metrics Largely Fail to Explain Cartilage Worsening in the Contralateral Knee in Persons with Unilateral Knee Osteoarthritis: The Multicenter Osteoarthritis Study - Corrigan, Patrick; Lewis, Cara; Costello, Kerry; Guermazi, Ali; Roemer, Frank; Kumar, Deepak; Felson, David; Bacon, Kathryn; Neogi, Tuhina; Lavalley, Michael; Nevitt, Michael; Lewis, Cora E.; et al. (ARTHRITIS & RHEUMATOLOGY, 2022)
CRIS-Team WoS Importer:2023-01-13

Three-dimensional mapping of the arteriovenous loop model using two-dimensional histological methods - Seuß, Hannes; Arkudas, Andreas; Hammon, Matthias; Bleiziffer, Oliver; Uder, Michael; Horch, Raymund E.; Yuan, Quan (Microscopy Research and Technique, 2016)
The aim of this study was to create an analytical tool for the three-dimensional distribution of immunohistochemically stained cells in the arteriovenous (AV) loop model of the femoral vessels of rats that fuses two-dimensional histological slides into stacks.A total of 22 AV loops were implanted into male syngeneic Lewis rats by creating an arteriovenous fistula between the femoral artery and vein by interposing a femoral vein graft of the contralateral extremity. This fistula was embedded into an isolation chamber filled with a fibrin matrix. Specimens were explanted after 7 to 14 days, and the AV loop was processed using standard histological protocols. Immunohistochemical staining for HIF-1? and a counter staining with hematoxylin was performed. Various layouts with different cutting planes, regions of interest, and post-processing algorithms were evaluated. Results and observations: The proximal-to-distal cutting perpendicular to the vascular axis proved to be the best layout for mapping the three-dimensional constructs containing the AV loop. A semi-automatic algorithm for the differentiation of immunohistochemical positive and negative cells was developed.The newly established methods from this study constitute an excellent tool for the general evaluation of the AV loop model - particularly with regard to the three-dimensional distribution of immunohistochemical positive and negative cells.
EVALuna2:14606

Threshold Isocontouring on High b-Value Diffusion-Weighted Images in Magnetic Resonance Mammography - Zong, Fangrong; Bickelhaupt, Sebastian; Kuder, Tristan Anselm; Lederer, Wolfgang; Daniel, Heidi; Stieber, Anne; Schlemmer, Heinz Peter; Galvosas, Petrik; Laun, Frederik Bernd (Journal of Computer Assisted Tomography, 2019)
OBJECTIVES: Motivated by the similar appearance of malignant breast lesions in high b-value diffusion-weighted imaging (DWI) and positron emission tomography, the purpose of this work was to evaluate the applicability of a threshold isocontouring approach commonly used in positron emission tomography to analyze DWI data acquired from female human breasts with minimal interobserver variability. METHODS: Twenty-three female participants (59.4 ± 10.0 years) with 23 lesions initially classified as suggestive of cancers in x-ray mammography screening were subsequently imaged on a 1.5-T magnetic resonance imaging scanner. Diffusion-weighted imaging was performed prior to biopsy with b values of 0, 100, 750, and 1500 s/mm. Isocontouring with different threshold levels was performed on the highest b-value image to determine the voxels used for subsequent evaluation of diffusion metrics. The coefficient of variation was computed by specifying 4 different regions of interest drawn around the lesion. Additionally, a receiver operating statistical analysis was performed. RESULTS: Using a relative threshold level greater than or equal to 0.85 almost completely suppresses the intra-individual and inter-individual variability. Among 4 studied diffusion metrics, the diffusion coefficients from the intravoxel incoherent motion model returned the highest area under curve value of 0.9. The optimal cut-off diffusivity was found to be 0.85 μm/ms with a sensitivity of 87.5% and specificity of 90.9%. CONCLUSION: Threshold isocontouring on high b-value maps is a viable approach to reliably evaluate DWI data of suspicious focal lesions in magnetic resonance mammography.
CRIS-Team Scopus Importer:2019-06-04

Thrombocytopenia and Clinical Outcomes in Intracerebral Hemorrhage: A Retrospective Multicenter Cohort Study - Mrochen, Anne; Sprügel, Maximilian; Gerner, Stefan; Sembill, Jochen; Lang, Stefan; Lücking, Hannes; Kuramatsu, Joji; Huttner, Hagen (Stroke, 2021)
BACKGROUND AND PURPOSE: The impact of platelets on hematoma enlargement (HE) of intracerebral hemorrhage (ICH) is not yet sufficiently elucidated. Especially the role of reduced platelet counts on HE and clinical outcomes is still poorly understood. This study investigated the influence of thrombocytopenia on HE, functional outcome, and mortality in patients with ICH with or without prior antiplatelet therapy (APT). METHODS: Individual participant data of multicenter cohort studies (multicenter RETRACE program [German-Wide Multicenter Analysis of Oral Anticoagulation-Associated Intracerebral Hemorrhage] and single-center UKER-ICH registry [Universitätsklinikum Erlangen Cohort of Patients With Spontaneous ICH]) were grouped into APT and non-APT ICH patients according to the platelet count, that is, with or without thrombocytopenia (cells <150×109/L). Of all patients, 51.5% (1124 of 2183) were on vitamin K antagonist. Imbalances in baseline characteristics including proportions of vitamin K antagonist patients were addressed using propensity score matching. Outcome analyses included HE (>33%), as well as mortality and functional outcome, after 3 months using the modified Rankin Scale, dichotomized into favorable (modified Rankin Scale score, 0-3) and unfavorable (modified Rankin Scale score, 4-6). RESULTS: Of overall 2252 ICH patients, 11.4% (52 of 458) under APT and 14.0% (242 of 1725) without APT presented with thrombocytopenia on admission. The proportion of patients with HE was not significantly different between patients with or without thrombocytopenia among APT and non-APT ICH patients after propensity score matching (HE: APT patients: 9 of 40 [22.5%] thrombocytopenia versus 27 of 115 [23.5%] nonthrombocytopenia, P=0.89; non-APT patients: 54 of 174 [31.0%] thrombocytopenia versus 106 of 356 [29.8%] nonthrombocytopenia, P=0.77). In both (APT and non-APT) propensity score matching cohorts, there were no significant differences regarding functional outcome. Mortality after 3 months did not differ among non-APT patients, whereas the mortality rate was significantly higher for APT patients with thrombocytopenia versus APT patients with normal platelet count (APT: 29 of 46 [63.0%] thrombocytopenia versus 58 of 140 [41.4%] nonthrombocytopenia, P=0.01; non-APT: 95 of 227 [41.9%] thrombocytopenia versus 178 of 455 [39.1%] nonthrombocytopenia, P=0.49). CONCLUSIONS: Our study implies that thrombocytopenia does not affect rates of HE and functional outcome among ICH patients, neither in patients with nor without APT. In light of increased mortality, the significance of platelet transfusions for ICH patients with thrombocytopenia and previous APT should be explored in future studies.
CRIS-Team Scopus Importer:2021-04-19
Keywords: cohort studies; hematoma enlargement; intracerebral hemorrhage; platelet count; thrombocytopenia

Tibial tuberosity to trochlear groove distance and its association with patellofemoral osteoarthritis-related structural damage worsening: data from the osteoarthritis initiative - Haj-Mirzaian, Arya; Guermazi, Ali; Hakky, Michael; Sereni, Christopher; Zikria, Bashir; Roemer, Frank; Tanaka, Miho J.; Cosgarea, Andrew J.; Demehri, Shadpour (European Radiology, 2018)
OBJECTIVES: To determine whether the tibial tuberosity-to-trochlear groove (TT-TG) distance is associated with concurrent patellofemoral joint osteoarthritis (OA)-related structural damage and its worsening on 24-month follow-up magnetic resonance imaging (MRI) in participants in the Osteoarthritis Initiative (OAI). METHODS: Six hundred subjects (one index knee per participant) were assessed. To evaluate patellofemoral OA-related structural damage, baseline and 24-month semiquantitative MRI Osteoarthritis Knee Score (MOAKS) variables for cartilage defects, bone marrow lesions (BMLs), osteophytes, effusion, and synovitis were extracted from available readings. The TT-TG distance was measured in all subjects using baseline MRIs by two musculoskeletal radiologists. The associations between baseline TT-TG distance and concurrent baseline MOAKS variables and their worsening in follow-up MRI were investigated using regression analysis adjusted for variables associated with tibiofemoral and patellofemoral OA. RESULTS: At baseline, increased TT-TG distance was associated with concurrent lateral patellar and trochlear cartilage damages, BML, osteophytes, and knee joint effusion [cross-sectional evaluations; overall odds ratio 95% confidence interval (OR 95% CI): 1.098 (1.045-1.154), p < 0.001]. In the longitudinal analysis, increased TT-TG distance was significantly related to lateral patellar and trochlear cartilage, BML, and joint effusion worsening (overall OR 95% CI: 1.111 (1.056-1.170), p < 0.001). CONCLUSIONS: TT-TG distance was associated with simultaneous lateral patellofemoral OA-related structural damage and its worsening over 24 months. Abnormally lateralized tibial tuberosity may be considered as a risk factor for future patellofemoral OA worsening. KEY POINTS: • Excessive TT-TG distance on MRI is an indicator/predictor of lateral-patellofemoral-OA. • TT-TG is associated with simultaneous lateral-patellofemoral-OA (6-17% chance-increase for each millimeter increase). • TT-TG is associated with longitudinal (24-months) lateral-patellofemoral-OA (5-15% chance-increase for each millimeter).
EVALuna2:35380

Time-dependent risk factors for epileptic seizures in glioblastoma patients: A retrospective analysis of 520 cases - Stritzelberger, Jenny; Gesmann, Anna; Fuhrmann, Imke; Brandner, Sebastian; Welte, Tamara; Balk, Stefanie; Eisenhut, Felix; Dörfler, Arnd; Coras, Roland; Adler, Werner; Schwab, Stefan; Putz, Florian; et al. (Epilepsia, 2023)
Objective: Epilepsy is a common comorbidity of glioblastoma. Seizures may occur in various phases of the disease. We aimed to assess potential risk factors for seizures in accordance with the point in time at which they occurred. Methods: We retrospectively analyzed medical files of adult patients with de novo glioblastoma treated at our institution between January 2006 and January 2020. We categorized seizures as preoperative seizures (POS), early postoperative seizures (EPS; before initiation of radio[chemo]therapy [RCT]), seizures during radiotherapy (SDR; during or <30 days after RCT), and posttherapeutic seizures (PTS; ≥30 days after completion of RCT). We addressed associations between patients' characteristics and their seizures. Results: In the final cohort (N = 520), 292 patients experienced seizures. POS, EPS, SDR, and/or PTS occurred in 29.6% (154/520), 6.0% (31/520), 13.8% (70/509), and 36.1% (152/421) of patients, respectively. POS occurred more frequently in patients with higher Karnofsky Performance Scale scores (odds ratio [OR] = 3.27, p =.001) and tumor location in the temporal lobe (OR = 1.51, p =.034). None of the parameters we analyzed was related to the occurrence of EPS. SDR were independently associated with tumor location (parietal lobe, OR = 1.86, p =.027) and POS, but not EPS, and were independent of RCT. PTS were independently associated with tumor progression (OR = 2.32, p <.001) and with occurrence of SDR (OR = 3.36, p <.001), and negatively correlated with temporal lobe location (OR =.58, p <.014). In patients with tumors exclusively located in the temporal lobe, complete tumor resection was associated with a decreased risk of postoperative seizures. Significance: Seizures in glioblastoma patients have various, time-dependent risk factors. Temporal lobe localization was a risk factor for preoperative seizures; surgery may have had a protective effect in these patients. RCT did not have dose-dependent pro- or anticonvulsive effects. PTS were associated with tumor progression.
CRIS-Team Scopus Importer:2023-07-07
Keywords: glioblastoma; radiochemotherapy; seizures; surgery

Time-extended local rtPA infiltration for acutely thrombosed hemodialysis fistulas - Regus, Susanne; Lang, Werner; Heinz, Marco; Rother, Ulrich; Meyer, Alexander; Almási-Sperling, Veronika; Uder, Michael; Schmid, Axel (Hemodialysis International, 2018)
This study describes results of a modified local thrombolysis technique for acutely thrombosed hemodialysis (HD) arteriovenous fistulas (AVF), which is characterized by prolonged recombinant tissue plasminogen activator (rtPA) local exposure times. Contrary to the standard lyse- and- wait (L&W) technique with local reaction times of 20-40 minutes, the modified protocol allows timing of challenging angioplasty maneuvers to the next regular working day.From February 2009 to April 2014, 84 patients on HD presented with 152 acutely thrombosed AVF. They proceeded to local thrombolysis including a single shot infiltration of rtPA, local reaction time up to 40 hours and finally percutaneous stenosis angioplasty. Success rates, major adverse events and need for temporary catheter placements (TCP) were retrospectively analyzed.The local thrombolysis time after single shot infiltration was 18.6 ± 6.2 (range 2-40) hours. Mean rtPA- dosage was 2.7 mg ± 1.2. The overall success rate was 89.5% and the major complication rate was 3.3%, whereas TCP was necessary in 12.5%. The PP/SP at 1, 3, 6, 12, 18, and 24 month were 86% ± 3%/95% ± 2%, 68% ± 4%/92% ± 2%, 43% ± 4%/90% ± 2%, 28% ± 4%/82% ± 3%, 12% ± 3%/82% ± 3%, 7% ± 2%/63% ± 4%, respectively.The modified L&W technique with prolonged local rtPA reaction times is a safe and effective declotting procedure. The need for TCP was not increased and therefore comparable to the standard technique.
EVALuna2:15322

Time-of-Flight Angiography in Ultra-High-Field 7 T MRI for the Evaluation of Peroneal Perforator Arteries Before Osseomyocutaneous Flap Surgery - Wiesmüller, Marco; Meixner, Christian; Weber, Manuel; Kesting, Marco Rainer; Nagel, Armin M.; Wüst, Wolfgang; May, Matthias; Roemer, Frank W.; Uder, Michael; Heiß, Rafael (Investigative Radiology, 2023)
OBJECTIVES: Presurgical identification and morphologic characterization of the peroneal perforator arteries (PPAs) are essential for osseomyocutaneous flap surgery. The aim of this study was to evaluate PPAs using time-of-flight (TOF) angiography in 7 T magnetic resonance imaging in comparison with dual-energy computed tomographic angiography (CTA). MATERIALS AND METHODS: In this prospective study, TOF angiography and CTA of both lower legs were acquired before flap surgery from 07/2019 to 02/2020. Magnetic resonance imaging was performed using a dedicated 28-channel knee coil with an acquisition time of 9:55 minutes (voxel size: 0.4 × 0.4 × 0.8 mm). Computed tomographic angiography was acquired with a third-generation dual-source computed tomography on the same day. Virtual monoenergetic reconstructions at 40 keV photon energy served as the standard of reference for PPA identification and subtyping. Two independent readers assessed the image quality, quantity, length assessment, and classification according to surgical considerations of PPAs for TOF angiography and CTA. Both TOF angiography and CTA were used for presurgical flap design and were evaluated by an orofacial surgeon. RESULTS: Ten patients (mean age, 59.9 ± 14.9 years; 7 men) were included. Time-of-flight angiography and CTA identified 53 and 51 PPAs in total, respectively. Time-of-flight angiography showed superior image quality (both readers, P < 0.05). Time-of-flight angiography enabled specific classification of PPA subtypes more often (53 vs 39; P < 0.05), and both readers reported higher diagnostic confidence for TOF angiography than CTA in all patients (interrater agreement κ = 0.8; P < 0.05). Regarding length assessment, PPAs were significantly more conspicuous with TOF angiography (TOF mean , 50 ± 11 mm; CTA mean , 40 ± 9 mm; P = 0.001). In comparison with CTA, TOF angiography prospectively changed the orofacial surgeon's final decision on the presurgical selected PPAs in 60% of cases. CONCLUSIONS: Presurgical assessment of PPAs is feasible using TOF in 7 T magnetic resonance imaging. Moreover, TOF angiography was superior to CTA for classifying and identifying PPAs, which may facilitate the planning of reconstructive surgery.
CRIS-Team Scopus Importer:2023-02-24

Time-Resolved C-Arm Computed Tomographic Angiography Derived From Computed Tomographic Perfusion Acquisition: New Capability for One-Stop-Shop Acute Ischemic Stroke Treatment in the Angiosuite - Yang, Pengfei; Niu, Kai; Wu, Yijing; Struffert, Tobias; Dörfler, Arnd; Schafer, Sebastian; Royalty, Kevin; Strother, Charles; Chen, Guang-Hong (Stroke, 2015)
Multimodal imaging using cone beam C-arm computed tomography (CT) may shorten the delay from ictus to revascularization for acute ischemic stroke patients with a large vessel occlusion. Largely because of limited temporal resolution, reconstruction of time-resolved CT angiography (CTA) from these systems has not yielded satisfactory results. We evaluated the image quality and diagnostic value of time-resolved C-arm CTA reconstructed using novel image processing algorithms.Studies were done under an Institutional Review Board approved protocol. Postprocessing of data from 21 C-arm CT dynamic perfusion acquisitions from 17 patients with acute ischemic stroke were done to derive time-resolved C-arm CTA images. Two observers independently evaluated image quality and diagnostic content for each case. ICC and receiver-operating characteristic analysis were performed to evaluate interobserver agreement and diagnostic value of this novel imaging modality.Time-resolved C-arm CTA images were successfully generated from 20 data sets (95.2%, 20/21). Two observers agreed well that the image quality for large cerebral arteries was good but was more limited for small cerebral arteries (distal to M1, A1, and P1). receiver-operating characteristic curves demonstrated excellent diagnostic value for detecting large vessel occlusions (area under the curve=0.987-1).Time-resolved CTAs derived from C-arm CT perfusion acquisitions provide high quality images that allowed accurate diagnosis of large vessel occlusions. Although image quality of smaller arteries in this study was not optimal ongoing modifications of the postprocessing algorithm will likely remove this limitation. Adding time-resolved C-arm CTAs to the capabilities of the angiography suite further enhances its suitability as a one-stop shop for care for patients with acute ischemic stroke.
EVALuna2:23004

Tissue sodium concentration correlates with hypertrophic vascular remodelling in type 2 diabetes - Kannenkeril, D.; Jung, Susan; Harazny, Jeremy; Striepe, Kristina; Ott, Christian; Linz, Peter; Nagel, Armin Michael; Uder, Michael; Schmieder, Roland (DIABETOLOGIA, 2019)
CRIS-Team WoS Importer:2019-10-11

Tissue sodium concentration emerged as a determinant of hypertrophic vascular remodeling in type 2 diabetes - Schmieder, Roland; Jung, Susanne; Kannenkeril, D.; Harazny, J. M.; Striepe, Kristina; Ott, Christian; Linz, Peter; Nagel, Angela; Uder, Michael (EUROPEAN HEART JOURNAL, 2019)
CRIS-Team WoS Importer:2020-02-04

Tissue Sodium Concentration Quantification at 7.0-T MRI as an Early Marker for Chemotherapy Response in Breast Cancer: A Feasibility Study - Zaric, Olgica; Farr, Alex; Minarikova, Lenka; Lachner, Sebastian; Asseryanis, Ella; Nagel, Armin Michael; Weber, Michael; Singer, Christian F.; Trattnig, Siegfried (Radiology, 2021)
Background Tissue sodium concentration (TSC) is elevated in breast cancer and can determine chemotherapy response. Purpose To test the feasibility of using a sodium 23 (23Na) MRI protocol at 7.0 T for TSC quantification to predict early treatment outcomes of neoadjuvant chemotherapy in breast cancer and to determine whether those quantitative values provide additional information about efficacy. Materials and Methods Women with primary breast cancer were included in this prospective study. From July 2017 to June 2018, participants underwent 7.0-T 23Na MRI. Multichannel data sets were acquired with a density-adapted, three-dimensional radial projection reconstruction pulse sequence. Two-dimensional tumor size and TSC were evaluated before and after the first and second chemotherapy cycle, and statistical tests were performed based on the presence or absence of a pathologic complete response (pCR). Results Fifteen women with breast cancer and six healthy women were enrolled. The mean baseline tumor size in women with a pCR was 7.0 cm2 ± 5.0 (standard deviation), and the mean baseline tumor size in women without a pCR was 19.0 cm2 ± 12.0. After the first chemotherapy cycle, women with a pCR showed a reduced tumor size of 32.9% (2.3 cm2/7.0 cm2), compared with 15.3% (2.9 cm2/19.0 cm2) in those without a pCR. The areas under the receiver operating characteristic curve for tumor size reduction after the first and second chemotherapy cycle were 0.73 (95% CI: 0.09, 0.50; P = .12) and 0.93 (95% CI: 0.04, 0.60; P < .001), respectively. Women with a pCR had a mean baseline TSC of 69.4 mmol/L ± 6.1, with a reduction of 12.0% (8.3 mmol/L), whereas those without a pCR had a mean baseline TSC of 71.7 mmol/L ± 5.7, with a reduction of 4.7% (3.4 mmol/L) after the first cycle. The areas under the receiver operating characteristic curve for TSC after the first and second cycles were 0.96 (95% CI: 0.86, 1.00; P < .001) and 1.000 (95% CI: 1.00, P < .001), respectively. Conclusion Using 7.0-T MRI for tissue sodium concentration quantification to predict early treatment outcomes of neoadjuvant chemotherapy in breast cancer is feasible, with reduced tissue sodium concentration indicative of cancer response. © RSNA, 2021 Online supplemental material is available for this article.
CRIS-Team Scopus Importer:2021-04-09

Tissue Sodium Content and Arterial Hypertension in Obese Adolescents - Roth, Sophie; Marko, Lajos; Birukov, Anna; Hennemuth, Anja; Kuehnen, Peter; Jones, Alexander; Ghorbani, Niky; Linz, Peter; Mueller, Dominik N.; Wiegand, Susanna; Berger, Felix; Kuehne, Titus; et al. (Journal of Clinical Medicine, 2019)
Early-onset obesity is known to culminate in type 2 diabetes, arterial hypertension and subsequent cardiovascular disease. The role of sodium (Na+) homeostasis in this process is incompletely understood, yet correlations between Na+ accumulation and hypertension have been observed in adults. We aimed to investigate these associations in adolescents. A cohort of 32 adolescents (13-17 years), comprising 20 obese patients, of whom 11 were hypertensive, as well as 12 age-matched controls, underwent Na-23-MRI of the left lower leg with a standard clinical 3T scanner. Median triceps surae muscle Na+ content in hypertensive obese (11.95 mmol/L [interquartile range 11.62-13.66]) was significantly lower than in normotensive obese (13.63 mmol/L [12.97-17.64]; p = 0.043) or controls (15.37 mmol/L [14.12-16.08]; p = 0.012). No significant differences were found between normotensive obese and controls. Skin Na+ content in hypertensive obese (13.33 mmol/L [11.53-14.22] did not differ to normotensive obese (14.12 mmol/L [13.15-15.83]) or controls (11.48 mmol/L [10.48-12.80]), whereas normotensive obese had higher values compared to controls (p = 0.004). Arterial hypertension in obese adolescents is associated with low muscle Na+ content. These findings suggest an early dysregulation of Na+ homeostasis in cardiometabolic disease. Further research is needed to determine whether this association is causal and how it evolves in the transition to adulthood.
CRIS-Team WoS Importer:2020-01-28

Tissue sodium content correlates with hypertrophic vascular remodeling in type 2 diabetes - Kannenkeril, Dennis; Jung, Susanne; Harazny, Joanna; Striepe, Kristina; Ott, Christian; Dahlmann, Anke; Kopp, Christoph; Schiffer, Mario; Linz, Peter; Nagel, Armin Michael; Uder, Michael; Schmieder, Roland (Journal of Diabetes and Its Complications, 2021)
Background: Prospective studies describe a linkage between increased sodium intake and higher incidence of cardiovascular organ damage and end points. We analyzed whether tissue sodium content in the skin and muscles correlate with vascular hypertrophic remodeling, a risk factor for cardiovascular disease.
CRIS-Team WoS Importer:2021-12-03

Tissue sodium content in hypertension and related organ damage - Kolwelter, Julie; Uder, Michael; Schmieder, Roland (Journal of Hypertension, 2020)
Most textbooks state that sodium (Na) accumulation goes hand in hand with fluid retention to maintain the environmental isotonicity. In the last century, several studies found, however, that Na is stored in the extravascular space leading to an activation of the monocyte phagocytic system cells that work as a regulator of the interstitial electrolyte homeostasis. Na-23-MRI was developed to quantify noninvasively, accurately and reliably tissue Na content. In this review, we give an up-to-date overview of clinical studies utilizing this Na-23-MRI technique to elucidate the importance of tissue Na content in patients with cardiovascular risk factors leading to microvascular and macrovascular complications. Na storage leads ultimately to organ damage such as left ventricular hypertrophy or hypertrophic vascular remodeling of resistance vessels. Elevated Na content in muscle and skin has been detected in patients with treatment resistant hypertension, type 2 diabetes mellitus, acute and chronic heart failure, chronic kidney disease and end-stage renal failure. Pharmacological interventions have shown that a mobilization of extracellular accumulated Na is possible and may emerge as a new therapeutic approach in some diseases.
CRIS-Team WoS Importer:2021-01-01

Tissue sodium content in patients with type 2 diabetes mellitus - Kannenkeril, Dennis; Karg, Marina V.; Bosch, Agnes; Ott, Christian; Linz, Peter; Nagel, Armin Michael; Uder, Michael; Schmieder, Roland (Journal of Diabetes and Its Complications, 2019)
Background: Tissue sodium content by 23 Na magnetic resonance imaging (MRI)has been found to be increased in arterial hypertension. We analyzed whether tissue sodium content is increased in patients with type-2 diabetes (T2DM). Methods: Patients with T2DM were compared to those with primary hypertension. Patients with T2DM were off any antidiabetic and hypertensive patients off any antihypertensive therapy for at least 4 weeks. Skin and muscle sodium content was assessed non-invasively with a 3.0 T clinical MRI system (Magnetom Verio, Siemens Health Care, Erlangen, Germany)in each patient. Results: In patients with T2DM (N = 59)we observed significantly greater muscle sodium content (diabetes: 20.6 ± 3.5 vs hypertension: 16.3 ± 2.5 mmol/l, p < 0.001)and skin sodium content (diabetes: 24.5 ± 7.2 vs hypertension: 20.6 ± 5.7 mmol/l, p = 0.01)than in those with primary hypertension (N = 33). When potential confounders (age, body mass index, gender, systolic and diastolic blood pressure, estimated glomerular filtration rate)were entered in a covariance analysis, both skin sodium content (p = 0.037)and muscle sodium content (p < 0.001)were still clearly elevated. Conclusion: Patients with T2DM have greater skin and muscle sodium content. These are the first known data to demonstrate increased tissue sodium content in patients with T2DM, measured by 23 Na magnetic resonance imaging. Since tissue sodium content is related to organ damage, therapeutic intervention should aim at reducing tissue sodium content.
CRIS-Team Scopus Importer:2019-05-21
Keywords: 23Na-MRI; T2DM; Tissue sodium content; Salt; Sodium retention

Tolvaptan treatment in an adult Fontan patient with protein-losing enteropathy: a serial 23Na-MRI investigation - Moosmann, Julia; Toka, Okan; Linz, Peter; Dahlmann, Anke; Nagel, Armin M.; Schiffer, Mario; Uder, Michael; Cesnjevar, Robert; Dittrich, Sven; Kopp, Christoph (Therapeutic Advances in Chronic Disease, 2021)
Background: Protein-losing enteropathy (PLE) is a severe complication of the univentricular Fontan circulation and associated with disturbances in salt and water homeostasis. Fontan patients with PLE have a poor prognosis, with increased morbidity and mortality. Due to limited therapeutic strategies, patients are often treated only symptomatically. Methods: We report our first experience of Tolvaptan (TLV) treatment in a Fontan patient with PLE, severe volume retention and hyponatraemia, refractory to conventional diuretic therapy. In addition to clinical parameters, we monitored drug effects including tissue sodium and volume status via serial 23Na-magnetic resonance imaging (23Na-MRI) and bioimpedance spectroscopy compared with age-matched controls. Results: 23Na-MRI identified elevated tissue sodium, which decreased under TLV treatment, as well as volume status, while serum sodium increased and the patient’s symptoms improved. During long-term treatment, we were able to differentiate between sodium and volume status in our patient, suggesting that TLV uncoupled body sodium from water. Conclusion: TLV in addition to loop diuretics improved clinical symptoms of PLE and lowered tissue sodium overload. Long-term effects should be further evaluated in Fontan patients.
CRIS-Team Scopus Importer:2021-04-30
Keywords: Congenital heart disease; Fontan; RAAS; Tolvaptan

Tomosynthese - Schulz-Wendtland, Rüdiger; Beckmann, Matthias; Fasching, Peter; Uder, Michael (Chirurgische Praxis, 2016)
Full field digital mammography (FFDM) is the most important method for early diagnosis of breast cancer. The typical overlapping of normal and pathological tissue during the standard 2D projection, however, often reduces the specificity and sensitivity of the mammographic investigation. Digital breast tomosynthesis (DBT) provides on the basis of a limited number of single images with different projection angles not superimposed tomograms and may remove the unwanted masking by superimposed structures. Clinical studies show that the digital tomosynthesis has the real potential to reduce the recall rate and simultaneously increase the cancer detection rate, especially in women with dense breasts (detection and volumetry). The use of tomosynthesis seems to be superior to full field digital mammography in mammography screening. Other possibilities of the tomosynthesis are the dual energy mammography, contrast medium-enhanced mammography and intervention.
CRIS-Team Scopus Importer:2023-03-08
Keywords: Contrast medium-enhanced mammography; Dual energy mammography; Full-field digital mammography; Intervention; Mammography screening; Tomosynthesis

Tophus resolution with pegloticase: a prospective dual-energy CT study - Araujo, Elizabeth G.; Bayat, Sara; Petsch, Christina; Englbrecht, Matthias; Faustini, Francesca; Kleyer, Arnd; Hueber, Axel; Lell, Michael; Dalbeth, Nicola; Manger, Bernhard; Schett, Georg; Rech, Juergen; et al. (RMD Open, 2015)
To investigate the effect of intensive lowering of serum uric acid (SUA) levels by pegloticase on the resolution of tophi in patients with refractory gout.Descriptive study in patients with refractory gout receiving pegloticase treatment. SUA levels were measured before and after each infusion. Dual-energy CT (DECT) scans were taken from all patients before the first infusion and after the last infusion. Computerised tophus volumes were calculated for the baseline and follow-up assessments and compared with each other.10 patients with refractory gout and baseline mean SUA level of 8.1 mg/dL were enrolled. Patients were treated for a mean of 13.3 weeks. Pegloticase effectively reduced tophi in all patients showing a decrease in volume by 71.4%. Responders, showing reduction of SUA level below 6 mg/dL during at least 80% of the treatment time, were virtually cleared from tophi (-94.8%). Dependent on their anatomical localisation, resolution of tophi showed different dynamics, with articular tophi showing fast, and tendon tophi slow, resolution.Tophi are highly sensitive to pegloticase treatment, particularly when located at articular sites. Debulking of disease and a tophus-free state can be reached within a few months of pegloticase treatment. DECT allows for comprehensively assessing tophus burden and monitoring treatment responses.
EVALuna2:13180

Touch Imprint Cytology and Stereotactically-Guided Core Needle Biopsy of Suspicious Breast Lesions: 15-Year Follow-up - Schulz-Wendtland, Rüdiger; Fasching, Peter; Bani, Mayada; Lux, Michael P.; Jud, Sebastian; Rauh, C.; Bayer, C.; Wachter, David; Hartmann, Arndt; Beckmann, Matthias; Uder, Michael; Löhberg, Christian (Geburtshilfe und Frauenheilkunde, 2016)
Introduction: Stereotactically-guided core needle biopsies (CNB) of breast tumours allow histological examination of the tumour without surgery. Touch imprint cytology (TIC) of CNB promises to be useful in providing same-day diagnosis for counselling purposes and for planning future surgery. Having addressed the issue of accuracy of immediate microscopic evaluation of TIC, we wanted to re-examine the usefulness of this procedure in light of the present health care climate of cost containment by incorporating the surgical 15-year follow-up data and outcome. Patients and Methods: From January until December 1996 we performed TIC in core needle biopsies of 173 breast tumours in 169 patients, consisting of 122 malignant and 51 benign tumours. Histology of core needle biopsies was proven by surgical histology in all malignant and in 5 benign tumours. Surgical breast biopsy was not performed in 46 patients with 46 benign lesions, as the histological result from the core needle biopsy and the result of the TIC were in agreement with the suspected diagnosis from the complementary breast diagnostics. A 15-year follow-up of these patients followed in 2013 and follow-up data was collected from 40 women. Results: In the 15-year follow-up of the 40 benign lesions primarily confirmed using CNB and TIC, a diagnostic sensitivity, specificity, positive and negative predictive value and accuracy of 100 % was found. Conclusion: TIC and stereotactically guided CNB showed excellent long-term follow-up in patients with benign breast lesions. The use of TIC to complement CNB can therefore provide immediate cytological diagnosis of breast lesions.
EVALuna2:6752

Toward accurate and fast velocity quantification with 3D ultrashort TE phase-contrast imaging - Degenhardt, Katja; Schmidt, Simon; Aigner, Christoph S.; Kratzer, Fabian J.; Seiter, Daniel P.; Müller, Max; Kolbitsch, Christoph; Nagel, Armin M.; Wieben, Oliver; Schaeffter, Tobias; Schulz-Menger, Jeanette; Schmitter, Sebastian (Magnetic Resonance in Medicine, 2024)
Purpose: Traditional phase-contrast MRI is affected by displacement artifacts caused by non-synchronized spatial- and velocity-encoding time points. The resulting inaccurate velocity maps can affect the accuracy of derived hemodynamic parameters. This study proposes and characterizes a 3D radial phase-contrast UTE (PC-UTE) sequence to reduce displacement artifacts. Furthermore, it investigates the displacement of a standard Cartesian flow sequence by utilizing a displacement-free synchronized-single-point-imaging MR sequence (SYNC-SPI) that requires clinically prohibitively long acquisition times. Methods: 3D flow data was acquired at 3T at three different constant flow rates and varying spatial resolutions in a stenotic aorta phantom using the proposed PC-UTE, a Cartesian flow sequence, and a SYNC-SPI sequence as reference. Expected displacement artifacts were calculated from gradient timing waveforms and compared to displacement values measured in the in vitro flow experiments. Results: The PC-UTE sequence reduces displacement and intravoxel dephasing, leading to decreased geometric distortions and signal cancellations in magnitude images, and more spatially accurate velocity quantification compared to the Cartesian flow acquisitions; errors increase with velocity and higher spatial resolution. Conclusion: PC-UTE MRI can measure velocity vector fields with greater accuracy than Cartesian acquisitions (although pulsatile fields were not studied) and shorter scan times than SYNC-SPI. As such, this approach is superior to traditional Cartesian 3D and 4D flow MRI when spatial misrepresentations cannot be tolerated, for example, when computational fluid dynamics simulations are compared to or combined with in vitro or in vivo measurements, or regional parameters such as wall shear stress are of interest.
CRIS-Team Scopus Importer:2024-01-12
Keywords: 4D flow MRI; displacement artifact; flow artifact; GIRF; gradient imperfections; PC-UTE

Toward a deep learning-based magnetic resonance imaging only workflow for postimplant dosimetry in I-125 seed brachytherapy for prostate cancer - Grigo, Johanna; Karius, Andre; Hanspach, Jannis; Mücke, Lion; Laun, Frederik B.; Huang, Yixing; Strnad, Vratislav; Fietkau, Rainer; Bert, Christoph; Putz, Florian (Brachytherapy, 2024)
Background and purpose: The current standard imaging-technique for creating postplans in seed prostate brachytherapy is computed tomography (CT), that is associated with additional radiation exposure and poor soft tissue contrast. To establish a magnetic resonance imaging (MRI) only workflow combining improved tissue contrast and high seed detectability, a deep learning-approach for automatic seed segmentation on MRI-scans was developed. Material and methods: Patients treated with I-125 seed brachytherapy received a postplan-CT and a 1.5 T MRI-scan on nominal day 30 after implantation. For MRI-based seed visualization, DIXON-sequences were acquired and deep learning-based quantitative susceptibility maps (QSM) were generated from 3D-gradient-echo-sequences from 20 patients. Seed segmentations created on CT served as ground truth. For automatic seed segmentation on MRI, a 3D nnU-net model was trained using QSM and DIXON, both solely and combined. Results: Of the implanted seeds 94.8 ± 2.4% were detected with deep learning automatic segmentation entrained on both QSM and DIXON data. Models trained on the individual sequence data-sets performed worse with detection rates of 87.5 ± 2.6% or 88.6 ± 7.5% for QSM and DIXON respectively. The seed centers identified on CT versus QSM and DIXON were on average 1.8 ± 1.3 mm apart. Postimplant dosimetry for evaluation of positioning inaccuracies revealed only small variations of up to 0.4 ± 4.26 Gy in D90 (dose 90% of the prostate receives) between the standard CT-approach and our MRI-only workflow. Conclusion: The proposed deep learning-based MRI-only workflow provided a promisingly accurate and robust seed localization and thus has the potential to compete with current state-of-the-art CT-based postimplant dosimetry in the future.
CRIS-Team Scopus Importer:2024-02-02
Keywords: Magnetic resonance imaging; Magnetic resonance only workflow; Permanent brachytherapy; Postimplant dosimetry; Radiotherapy; Seed brachytherapy

Towards accelerated quantitative sodium MRI at 7 T in the skeletal muscle: Comparison of anisotropic acquisition- and compressed sensing techniques - Utzschneider, Matthias; Müller, Max; Gast, Lena; Lachner, Sebastian; Behl, Nicolas G.R.; Maier, Andreas; Uder, Michael; Nagel, Armin Michael (Magnetic Resonance Imaging, 2021)
Purpose: To compare three anisotropic acquisition schemes and three compressed sensing (CS) approaches for accelerated tissue sodium concentration (TSC) quantification using 23Na MRI at 7 T. Materials and methods: Three anisotropic 3D-radial acquisition sequences were evaluated using simulations, phantom- and in vivo TSC measurements: An anisotropic density-adapted 3D-radial sequence (3DPR-C), a 3D acquisition-weighted density-adapted stack-of-stars sampling scheme (SOS) and a SOS approach with golden-ratio rotation (SOS-GR). Eight healthy volunteers were examined at a 7 Tesla MRI system. TSC measurements of the calf were conducted with a nominal spatial resolution of Δx = (3.0 × 3.0 × 15.0) mm3 and a field of view of (156.0 × 156.0 × 240.0) mm3 for multiple undersampling factors (USF). Three CS reconstructions were evaluated: Total variation CS (TV-CS), 3D dictionary-learning compressed sensing (3D-DLCS) and TV-CS with a block matching prior (TV-BL-CS). Results of the simulations and measurements were compared to a simulated ground truth (GT) or a fully sampled reference measurement (FS), respectively. The deviation of the mean TSC evaluated in multiple ROI (mEGT/FS) and the normalized root-mean-squared error (NRMSE) for simulations were evaluated for CS and NUFFT reconstructions. Results: In simulations, the SOS-GR yielded the lowest NRMSE and mEGT (< 4%) with NUFFT for an acquisition time (TA) of less than 2 min. CS further improved the results. In simulations and measurements, the best TSC quantification results were obtained with 3D-DLCS and SOS-GR (lowest NRMSE, mEGT < 2.6% in simulations, mEGT < 10.7% for phantom measurements and mEFS < 6% in vivo) with an USF = 4.1 (TA < 2 min). TV-CS showed no or only slight improvements to NUFFT. The results of TV-BL-CS were similar to 3D-DLCS. Discussion: The TA for TSC measurements could be reduced to less than 2 min by using adapted sequences such as SOS-GR and CS reconstruction approaches such as 3D-DLCS or TV-BL-CS, while the quantitative accuracy stays comparable to a fully sampled NUFFT reconstruction (approx. 8 min TA). In future, the lower TA could improve clinical applicability of TSC measurements.
CRIS-Team Scopus Importer:2020-11-06
Keywords: 7 tesla; Anisotropic acquisition schemes; Compressed sensing; Image reconstruction; Skeletal muscle; Sodium (

Towards Automatic Abdominal Multi-Organ Segmentation in Dual Energy CT using Cascaded 3D Fully Convolutional Network - Chen, Shuqing; Roth, Holger; Dorn, Sabrina; May, Matthias; Lell, Michael; Kachelriess, Marc; Oda, Hirohisa; Mori, Kensaku; Maier, Andreas; Cavallaro, Alexander Josef (the fifth edition of The International Conference on Image Formation in X-ray Computed Tomography, 2018)
UnivIS-Import:2018-09-06:Pub.2018.tech.IMMD.IMMD5.toward_16

Towards prevention of post-traumatic osteoarthritis: report from an international expert working group on considerations for the design and conduct of interventional studies following acute knee injury - Watt, F. E.; Corp, Nadia; Kingsbury, S. R.; Frobell, R.; Englund, Martin; Felson, D. T.; Levesque, M.; Majumdar, S.; Wilson, C.; Beard, D. J.; Lohmander, L. S.; Kraus, V. B.; et al. (Osteoarthritis and Cartilage, 2019)
OBJECTIVE: There are few guidelines for clinical trials of interventions for prevention of post-traumatic osteoarthritis (PTOA), reflecting challenges in this area. An international multi-disciplinary expert group including patients was convened to generate points to consider for the design and conduct of interventional studies following acute knee injury. DESIGN: An evidence review on acute knee injury interventional studies to prevent PTOA was presented to the group, alongside overviews of challenges in this area, including potential targets, biomarkers and imaging. Working groups considered pre-identified key areas: eligibility criteria and outcomes, biomarkers, injury definition and intervention timing including multi-modality interventions. Consensus agreement within the group on points to consider was generated and is reported here after iterative review by all contributors. RESULTS: The evidence review identified 37 studies. Study duration and outcomes varied widely and 70% examined surgical interventions. Considerations were grouped into three areas: justification of inclusion criteria including the classification of injury and participant age (as people over 35 may have pre-existing OA); careful consideration in the selection and timing of outcomes or biomarkers; definition of the intervention(s)/comparator(s) and the appropriate time-window for intervention (considerations may be particular to intervention type). Areas for further research included demonstrating the utility of patient-reported outcomes, biomarkers and imaging outcomes from ancillary/cohort studies in this area, and development of surrogate clinical trial endpoints that shorten the duration of clinical trials and are acceptable to regulatory agencies. CONCLUSIONS: These considerations represent the first international consensus on the conduct of interventional studies following acute knee joint trauma.
EVALuna2:36226

Towards Real-time Guidewire Detection and Tracking in the Field of Neuroradiology - Spiegel, Martin; Pfister, Markus; Hahn, Dieter; Daum, Volker; Hornegger, Joachim; Struffert, Tobias; Dörfler, Arnd (Medical Imaging 2009: Biomedical Applications in Molecular, Structural, and Functional Imaging, 2009)
Two-dimensional roadmapping is considered state-of-the-art in guidewire navigation during endovascular interventions. This paper presents a methodology for extracting the guidewire from a sequence of 2-D roadmap images in almost real time. The detected guidewire can be used to improve its visibility on noisy fluoroscopic images or to do a back projection of the guidewire into a registered 3-D vessel tree. A lineness filter based on the Hessian matrix is used to detect only those line structures in the image that lie within the vessel tree. Loose wire fragments are properly linked by a novel connection method fulfilling clinical processing requirements. We show that Dijkstra's algorithm can be applied to efficiently compute the optimal connection path. The entire guidewire is finally approximated by a B-spline curve in a least-squares manner. The proposed method is both integrated into a commercial clinical prototype and evaluated on five different patient data sets containing up to 249 frames per image series. © 2009 SPIE.

Towards Super-resolution CEST MRI for Visualization of Small Structures - Folle, Lukas; Tkotz, Katharina; Gadjimuradov, Fasil; Kapsner, Lorenz; Fabian, Moritz; Bickelhaupt, Sebastian; Simon, David; Kleyer, Arnd; Krönke, Gerhard; Zaiß, Moritz; Nagel, Armin Michael; Maier, Andreas (Bildverarbeitung für die Medizin 2022, 2022)
The onset of rheumatic diseases such as rheumatoid arthritis is typically subclinical, which results in challenging early detection of the disease. However, characteristic changes in the anatomy can be detected using imaging techniques such as MRI or CT. Modern imaging techniques such as chemical exchange saturation transfer (CEST) MRI drive the hope to improve early detection even further through the imaging of metabolites in the body. To image small structures in the joints of patients, typically one of the first regions where changes due to the disease occur, a high resolution for the CEST MR imaging is necessary. Currently, however, CEST MR suffers from an inherently low resolution due to the underlying physical constraints of the acquisition. In this work we compared established up-sampling techniques to neural network-based super-resolution approaches. We could show, that neural networks are able to learn the mapping from low-resolution to high-resolution unsaturated CEST images considerably better than present methods. On the test set a PSNR of 32.29 dB (+10%), a NRMSE of 0.14 (+28%), and a SSIM of 0.85 (+15%) could be achieved using a ResNet neural network, improving the baseline considerably. This work paves the way for the prospective investigation of neural networks for super-resolution CEST MRI and, followingly, might lead to a earlier detection of the onset of rheumatic diseases.
Keywords: Deep Learning; Rheumatic diseases; Reconstruction

Toxic retrobulbar neuritis due to recurrent nonsteroidal antiinflammatory drug-exacerbated respiratory disease-based chronic sinusitis in the left sphenoid sinus: a case report - Schapher, Mirco; Brügel, Jacob; Güner, Fabian; Volbers, Bastian; Eichhorn, Philip; Agaimy, Abbas; Berger, Magdalena; Mardin, Christian; Dörfler, Arnd; Hock, Stefan (Journal of Medical Case Reports, 2023)
BACKGROUND: Abrupt visual impairment constitutes a medical urgency, necessitating an interdisciplinary diagnostic and therapeutic approach owing to the broad spectrum of potential etiologies, thereby engaging numerous medical specialties. CASE PRESENTATION: A 21-year-old Mixed White and Asian female patient, with medical history of nonsteroidal antiinflammatory drug-exacerbated respiratory disease necessitating previous sinus surgery, reported sudden monocular vision loss. Unremarkable ophthalmological examination of the fellow eye and hematological parameters, save for a slight elevation in lymphocytes and eosinophils, were observed. Imaging studies indicated recurrence of bilateral chronic rhinosinusitis with nasal polyps and a mucocele in the left sphenoid sinus, accompanied by bony structural deficits. Emergency revision sinus surgery, guided by navigation, was promptly performed. The patient received treatment with methylprednisolone, ceftriaxone, cyanocobalamin, pyridoxine, thiamine, and acetylsalicylic acid. During the hospital stay, she developed steroid-induced glaucoma, which was subsequently managed successfully. Negative microbiological swabs, along with pathohistological evidence of increased tissue eosinophilia and the patient's clinical history, led to the diagnosis of toxic retrobulbar neuritis secondary to recurrent nonsteroidal antiinflammatory drug-exacerbated respiratory disease-associated chronic rhinosinusitis of the left sphenoid sinus. CONCLUSIONS: In cases of acute unilateral vision loss, optic neuritis is a highly probable differential diagnosis and may be induced by pathologies of the paranasal sinuses. Nonsteroidal antiinflammatory drug-exacerbated respiratory disease, a subtype of chronic rhinosinusitis, is associated with type 2 inflammation, which is increasingly recognized for its role in the pathogenesis of bronchial asthma, eosinophilic esophagitis, and atopic eczema. Clinicians should consider chronic rhinosinusitis as a potential differential diagnosis in unilateral visual loss and be cognizant of the rising significance of type 2 inflammations, which are relevant to a variety of diseases.
CRIS-Team Scopus Importer:2023-08-11
Keywords: Blindness; Case report; Inflammation mediators; Neuritis; Optic; Sinusitis

TRABECULAR SUBCHONDRAL BONE ANALYSIS OF THE DISTAL RADIUS AT ULTRA-HIGH FIELD (7T) MRI: COMPARISON WITH 3T MRI AND RADIOGRAPHY - Jarraya, M.; Heiß, Rafael; Duryea, J.; Nagel, Armin Michael; Lynch, J. A.; Guermazi, A.; Weber, M. -A.; Arkudas, Andreas; Horch, Raymund E.; Uder, Michael; Roemer, Frank (OSTEOARTHRITIS AND CARTILAGE, 2021)
CRIS-Team WoS Importer:2021-05-21

Trainingsziele und Risikokategorisierung im Spannungsfeld körperliches Training und Frakturprophylaxe: Ansatzpunkte für individualisierte Trainingsprogramme - Mohebbi, Ramin; von Stengel, Simon; Kohl, Matthias; Jakob, Franz; Kerschan-Schindl, Katharina; Lange, Uwe; Peters, Stefan; Schöne, Daniel; Thomasius, Friederike; Becker, Clemens; Kladny, Bernd; Kemmler, Wolfgang (Osteologie, 2023)
In basic exercise science, defining relevant training aims and their individualized assignment to the specified subject or cohorts is the first step of any training strategy. In the complex area of exercise and fracture prevention, several aspects have to be considered. Whilst pharmaceutic therapy focuses solely on bone, exercise training aims for fracture prevention include all the main determinants (or reasons) of fractures, i. e. bone strength, fall frequency and fall-induced impact (on bone). However, the relevance of trainings aims covering maintenance or boosting bone strength, reduction of fall frequency and fall-induced impact differs significantly depending on the different cohorts at risk for fractures. In the present work, we differentiate five cohorts classified according to several aspects relating predominately to bone status, fall risk and physical capacity. When allocating the corresponding cohorts to their primary training aim(s), the primary training aim for (1) people with osteopenia and increased bone turnover without increased fall risk and for (2) people with osteoporosis, no fractures and without increased fall risk, is to maintain or increase bone strength. Reducing fall frequency and fall-related impact becomes increasingly relevant for cohorts with (3) people with osteoporosis, no fractures but multiple risk factors for falls and (4) people with vertebral fractures and multiple risk factors for falls. Finally, for (5) people with multiple fractures, high risk of falling and very low physical capacity, the relevance of bone strength as a training aim becomes negligible, partly because the majority of this cohort is provided with a pharmaceutic therapy that focuses on bone. We feel that the early and individualized assignment of training aims facilitates the further training process and represents a crucial aspect in the area of optimized training protocols for fracture prevention.
CRIS-Team Scopus Importer:2023-09-22
Keywords: cohort of risk for fractures; Exercise; fracture prevention; training aim; training regulation; type of exercise

Trajectory of cartilage loss within 4 years of knee replacement–a nested case-control study from the osteoarthritis initiative - Eckstein, F.; Boudreau, R. M.; Wang, Z.; Hannon, M. J.; Wirth, Wolfgang; Cotofana, S.; Guermazi, A.; Roemer, Frank; Nevitt, M.; John, M. R.; Ladel, C.; Sharma, L.; et al. (Osteoarthritis and Cartilage, 2014)
Knee replacement (KR) represents a clinically important endpoint of knee osteoarthritis (KOA). Here we examine the 4-year trajectory of femoro-tibial cartilage thickness loss prior to KR vs non-replaced controls.A nested case-control study was performed in Osteoarthritis Initiative (OAI) participants: Cases with KR between 12 and 60 month (M) follow-up were each matched with one control (without KR through 60M) by age, sex, and baseline radiographic stage. Femoro-tibial cartilage thickness was measured quantitatively using magnetic resonance imaging (MRI) at the annual visit prior to KR occurrence (T0), and at 1-4 years prior to T0 (T-1 to T-4). Cartilage loss between cases and controls was compared using paired t-tests and conditional logistic regression.One hundred and eighty-nine knees of 164 OAI participants [55% women; age 64 ± 8.7; body mass index (BMI) 29 ± 4.5] had KR and longitudinal cartilage data. Comparison of annualized slopes of change across all time points revealed greater loss in the central medial tibia (primary outcome) in KRs than in controls [94 ± 137 vs 55 ± 104 ?m; P = 0.0017 (paired t); odds ratio (OR) 1.36 (95% confidence interval (CI): 1.08-1.70)]. The discrimination was stronger for T-2 -> T0 [OR 1.61 (1.33-1.95), n = 127] than for T-1 -> T0, and was not statistically significant for intervals prior to T-2 [i.e., T-4 -> T-2, OR 0.97 (0.67-1.41), n = 60]. Results were similar for total medial femoro-tibial cartilage loss (secondary outcome), and when adjusting for pain and BMI.In knees with subsequent replacement, cartilage loss accelerates in the 2 years, and particularly in the year prior to surgery, compared with controls. Whether slowing this cartilage loss can delay KR remains to be determined.
EVALuna2:14554

Transcatheter Intervention of Bilateral Renal Artery Stenosis in an Infant after arterial Switch to Control Arterial Hypertension - Wiewrodt, B.; Dittrich, Sven; Uder, Michael; Wirbelauer, J. (Klinische Pädiatrie, 2016)
EVALuna2:14584

Transcription factor Fra-1 targets arginase-1 to enhance macrophage-mediated inflammation in arthritis - Hannemann, Nicole; Cao, Shan; Eriksson, Daniel; Schnelzer, Anne; Jordan, Jutta; Eberhardt, Martin; Schleicher, Ulrike; Rech, Jürgen; Uebe, Steffen; Ekici, Arif Bülent; Canete, Juan D.; Chen, Xiaoxiang; et al. (Journal of Clinical Investigation, 2019)
The polarization of macrophages is regulated by transcription factors, such as NF-κB and activator protein 1 (AP-1). In this manuscript, we delineated the role of the transcription factor Fos-related antigen 1 (Fra-1) during macrophage activation and development of arthritis. Network level interaction analysis of microarray data derived from Fra-1- or Fra-2-deficient macrophages revealed a central role of Fra-1, but not of Fra-2, in orchestrating the expression of genes related to wound response, Toll-like receptor activation, and interleukin signaling. ChIP sequencing and standard ChIP analyses of macrophages identified arginase 1 (Arg1) as a target of Fra-1. Luciferase reporter assays revealed that Fra-1 downregulated Arg1 expression by direct binding to the promoter region. Using macrophage-specific Fra-1- or Fra-2-deficient mice, we observed enhanced expression and activity of Arg1 and a reduction of arthritis in the absence of Fra-1, but not of Fra-2. This phenotype was reversed by treatment with the arginase inhibitor Nω-hydroxy-nor-arginine, while -arginine supplementation increased arginase activity and alleviated arthritis, supporting the notion that reduced arthritis in macrophage-specific Fra-1-deficient mice resulted from enhanced Arg1 expression and activity. Moreover, patients with active rheumatoid arthritis (RA) showed increased Fra-1 expression in the peripheral blood and elevated Fra-1 protein in synovial macrophages compared with RA patients in remission. In addition, the Fra-1/ARG1 ratio in synovial macrophages was related to RA disease activity. In conclusion, these data suggest that Fra-1 orchestrates the inflammatory state of macrophages by inhibition of Arg1 expression and thereby impedes the resolution of inflammation.
CRIS-Team Scopus Importer:2019-07-16

Transhepatic forceps biopsy after PTCD for histological assessment of bile duct stenoses or occlusions - Warnken, Eva-Marie; Uder, Michael; Stein, Hubert; Wucherer, Michael; Lell, Michael; Muschweck, Herbert; Adamus, Ralf (Zeitschrift für Gastroenterologie, 2019)
Purpose The goal of this study was to evaluate the experience of 11 years of wire-guided forceps biopsy via PTCD in patients with obstructive jaundice.
CRIS-Team WoS Importer:2019-03-12

Transient Enlargement in Meningiomas Treated with Stereotactic Radiotherapy - Maksoud, Ziad; Schmidt, Manuel; Huang, Yixing; Rutzner, Sandra; Mansoorian, Sina; Weissmann, Thomas; Bert, Christoph; Distel, Luitpold; Semrau, Sabine; Lettmaier, Sebastian; Eyüpoglu, Ilker Yasin; Fietkau, Rainer; et al. (Cancers, 2022)
To investigate the occurrence of pseudoprogression/transient enlargement in meningiomas after stereotactic radiotherapy (RT) and to evaluate recently proposed volumetric RANO meningioma criteria for response assessment in the context of RT. Sixty-nine meningiomas (benign: 90%, atypical: 10%) received stereotactic RT from January 2005–May 2018. A total of 468 MRI studies were segmented longitudinally during a median follow-up of 42.3 months. Best response and local control were evaluated according to recently proposed volumetric RANO criteria. Transient enlargement was defined as volumetric increase ≥20% followed by a subsequent regression ≥20%. The mean best volumetric response was −23% change from baseline (range, −86% to +19%). According to RANO, the best volumetric response was SD in 81% (56/69), MR in 13% (9/69) and PR in 6% (4/69). Transient enlargement occurred in only 6% (4/69) post RT but would have represented 60% (3/5) of cases with progressive disease if not accounted for. Transient enlargement was characterized by a mean maximum volumetric increase of +181% (range, +24% to +389 %) with all cases occurring in the first year post-RT (range, 4.1–10.3 months). Transient enlargement was significantly more frequent with SRS or hypofractionation than with conventional fractionation (25% vs. 2%, p = 0.015). Five-year volumetric control was 97.8% if transient enlargement was recognized but 92.9% if not accounted for. Transient enlargement/pseudoprogression in the first year following SRS and hypofractionated RT represents an important differential diagnosis, especially because of the high volumetric control achieved with stereotactic RT. Meningioma enlargement during subsequent post-RT follow-up and after conventional fractionation should raise suspicion for tumor progression. <
Keywords: meningioma; volumetric analysis; segmentation; transient enlargement; pseudoprogression; stereotactic radiotherapy; radiosurgery; response assessment

Transient naming deficits associated with insular lesions in a patient with encephalitis - Marxreiter, Franz; Utz, Kathrin; Schlachetzki, Johannes; Seifert, Frank; Schmidt, Manuel; Dörfler, Arnd; Schwab, Stefan; Schenk, Thomas (Neurocase, 2019)
We describe a patient with acute herpes simplex encephalitis with left-hemispheric hippocampal, parahippocampal and insular lesions. Although prototypic language areas were unaffected, the patient suffered from an inability to name objects or animals displayed on pictures. This deficit was transient and gradually disappeared 8 weeks after the initial diagnosis. Our findings are in line with a previous report showing similar deficits in a patient with a comparable lesion pattern and support the hypothesis that left insular lesions can produce severe naming deficits. Using FDG-PET we ruled out that functional deactivation in classical language areas account for the observed naming deficits.
EVALuna2:204482

Transvascular kidney biopsy in adolescent patients-safe alternative to open procedures - Utsch, Boris; Hoppe, Hanno; Dittrich, Katalin; Amann, Kerstin Ute; Gugger, Mathias; Tschumi, Sibylle; Galiano, Matthias; Plank, Christian Georg; Rascher, Wolfgang; Schmid, Axel; Uder, Michael; Dötsch, Jörg (Clinical Kidney Journal, 2021)
CRIS-Team WoS Importer:2021-05-21

Transvenous renal transplant biopsy via a transfemoral approach - Schmid, Axel; Jacobi, Johannes; Kuefner, M. A.; Lell, Michael; Wüst, Wolfgang; Mayer-Kadner, I.; Benz, Kerstin; Schmid, Matthias; Amann, Kerstin Ute; Uder, Michael (American Journal of Transplantation, 2013)
Percutaneous renal biopsy (PRB) of kidney transplants might be prevented by an elevated risk of bleeding or limited access to the allograft. In the following, we describe our initial experience with 71 transvenous renal transplant biopsies in 53 consecutive patients with unexplained reduced graft function who were considered unsuitable candidates for PRB (4.2% of all renal transplant biopsies at our institution). Biopsies were performed via the ipsilateral femoral vein with a renal biopsy set designed for transjugular renal biopsy (TJRB) of native kidneys. Positioning of the biopsy system within the transplant vein was achievable in 58 of 71 (81.7%) procedures. The specimen contained a median of 10 glomeruli (range 0-38). Tissue was considered as adequate for diagnosis in 56 of 57 (98.2%) biopsies. With respect to BANFF 50.9% of the specimen were adequate (>10 glomeruli), 47.4% marginally adequate (1-9 glomeruli) and 1.8% inadequate (no glomeruli). After implementation of real-time assessment all specimen contained glomeruli. One of the fifty-eight (1.8%) procedure-related major complications occurred (hydronephrosis requiring nephrostomy due to gross hematuria). Transfemoral renal transplant biopsy (TFRTB) is feasible and appears to be safe compared to PRB. It offers a useful new alternative for histological evaluation of graft dysfunction in selected patients with contraindications to PRB. The authors report on an experience using transvenous renal transplant biopsy to enable histological evaluation in patients unsuitable for percutaneous transplant biopsy. © 2013 The American Society of Transplantation and the American Society of Transplant Surgeons.
CRIS-Team Scopus Importer:2023-03-08
Keywords: Kidney transplant; percutaneous renal transplant biopsy; renal allograft; renal transplant biopsy; transjugular renal biopsy; transvenous biopsy

Treatment for acute anterior cruciate ligament tear: five year outcome of randomised trial - Frobell, Richard B.; Roos, Harald P.; Roos, Ewa M.; Roemer, Frank; Ranstam, Jonas; Lohmander, L. Stefan (British Journal of Sports Medicine, 2015)
In young active adults with an acute anterior cruciate ligament (ACL) rupture, do patient reported or radiographic outcomes after five years differ between those treated with rehabilitation plus early ACL reconstruction and those treated with rehabilitation and optional delayed ACL reconstruction?At five years, patients assigned to rehabilitation plus early ACL reconstruction did not differ significantly in patient reported or radiographic outcomes from those assigned to initial rehabilitation with the option of having a later reconstruction if needed.The relative efficacy of surgical reconstruction and rehabilitation for short and long term outcomes of ACL rupture is debated. Clinicians and young active adult patients should consider rehabilitation as a primary treatment option following an acute ACL tear.
EVALuna2:14540

Treatment of a patient with severe systemic sclerosis (SSc) using CD19-targeted CAR T cells. - Bergmann, Christina; Müller, Fabian; Distler, Jörg; Györfi, Andrea Hermina; Völkl, Simon; Aigner, Michael; Kretschmann, Sascha; Reimann, Hannah; Harrer, Thomas; Bayerl, Nadine; Böltz, Sebastian; Wirsching, Andreas; et al. (Annals of the Rheumatic Diseases, 2023)
EVALuna2:537682

Truncation correction for VOI C-arm CT using scattered radiation - Bier, Bastian; Maier, Andreas; Hofmann, Hannes; Schwemmer, Chris; Xia, Yan; Struffert, Tobias; Hornegger, Joachim (Medical Imaging 2013: Physics of Medical Imaging, 2013)
In C-arm computed tomography, patient dose reduction by volume-of-interest (VOI) imaging is of increasing interest for many clinical applications. A remaining limitation of VOI imaging is the truncation artifact when reconstructing a 3D volume. It can either be cupping towards the boundaries of the field-of-view (FOV) or an incorrect offset in the Hounsfield values of the reconstructed voxels. In this paper, we present a new method for correction of truncation artifacts in a collimated scan. When axial or lateral collimation are applied, scattered radiation still reaches the detector and is recorded outside of the FOV. If the full area of the detector is read out we can use this scattered signal to estimate the truncated part of the object. We apply three processing steps: detection of the collimator edge, adjustment of the area outside the FOV, and interpolation of the collimator edge. Compared to heuristic truncation correction methods we were able to reconstruct high contrast structures like bones outside of the FOV. Inside the FOV we achieved similar reconstruction results as with water cylinder truncation correction. These preliminary results indicate that scattered radiation outside the FOV can be used to improve image quality and further research in this direction seems beneficial. © 2013 SPIE.

Tumor Blood Vessel Visualization - Gillmann, Clarissa; Bäuerle, Tobias (Methods in Molecular Biology, 2016)
Noninvasive multimodal imaging of tumor blood vessels allows the qualitative and quantitative assessment of morphological, functional, and molecular features of tumor angiogenesis longitudinally in a living organism. In this chapter we focus on the application of magnetic resonance imaging (MRI), computed tomography (CT), ultrasound (US), and positron emission tomography (PET) in tumor blood vessel visualization on the example of breast cancer bone metastasis in a nude rat model. Thereby, materials and methods are described that are needed to obtain complementary data on tumor vascularization from these imaging techniques.
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Tumor budding: A predictor for metastasis in the CAM xenograft model - Muenzner, Julienne K.; Ranjan, Raphela A.; Eckstein, Markus; Erber, Ramona; Kunze, Philipp; Geppert, Carol-Immanuel; Rübner, Matthias; Bäuerle, Tobias; Hartmann, Arndt; Schneider-Stock, Regine (CANCER RESEARCH, 2019)
CRIS-Team WoS Importer:2019-10-22

Tumor immunoevasion via acidosis-dependent induction of regulatory tumor-associated macrophages - Bohn, Toszka; Rapp, Steffen; Luther, Natascha; Klein, Matthias; Bruehl, Till-Julius; Kojima, Nobuhiko; Lopez, Pamela Aranda; Hahlbrock, Jennifer; Muth, Sabine; Endo, Shogo; Pektor, Stefanie; Brand, Almut; et al. (Nature Immunology, 2018)
Many tumors evolve sophisticated strategies to evade the immune system, and these represent major obstacles for efficient antitumor immune responses. Here we explored a molecular mechanism of metabolic communication deployed by highly glycolytic tumors for immunoevasion. In contrast to colon adenocarcinomas, melanomas showed comparatively high glycolytic activity, which resulted in high acidification of the tumor microenvironment. This tumor acidosis induced Gprotein-coupled receptor-dependent expression of the transcriptional repressor ICER in tumor-associated macrophages that led to their functional polarization toward a non-inflammatory phenotype and promoted tumor growth. Collectively, our findings identify a molecular mechanism of metabolic communication between non-lymphoid tissue and the immune system that was exploited by high-glycolytic-rate tumors for evasion of the immune system.
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Tumor Therapy Monitoring Based on Monomodal Image Fusion - Hornegger, Joachim; Hahn, Dieter; Bautz, Werner; Kuwert, Torsten; Römer, Wolfgang (Proceedings of the Radiological Society of North America (RSNA 2004), 2005)

Twelve-year survival and immune correlates in dendritic cell-vaccinated melanoma patients - Gross, Stefanie; Erdmann, Michael; Haendle, Ina; Voland, Steve; Berger, Thomas; Schultz, Erwin; Strasser, Erwin; Dankerl, Peter; Janka, Rolf Matthias; Schliep, Stefan; Heinzerling, Lucie; Sotlar, Karl; et al. (JCI Insight, 2017)
BACKGROUND: Reports on long-term (≥10 years) effects of cancer vaccines are missing. Therefore, in 2002, we initiated a phase I/II trial in cutaneous melanoma patients to further explore the immunogenicity of our DC vaccine and to establish its long-term toxicity and clinical benefit after a planned 10-year followup. METHODS: Monocyte-derived DCs matured by TNFα, IL-1β, IL-6, and PGE2 and then loaded with 4 HLA class I and 6 class II-restricted tumor peptides were injected intradermally in high doses over 2 years. We performed serial immunomonitoring in all 53 evaluable patients. RESULTS: Vaccine-specific immune responses including high-affinity, IFNγ-producing CD4+ and lytic polyfunctional CD8+ T cells were de novo induced or boosted in most patients. Exposure of mature DCs to trimeric soluble CD40 ligand, unexpectedly, did not further enhance such immune responses, while keyhole limpet hemocyanin (KLH) pulsing to provide unspecific CD4+ help promoted CD8+ T cell responses - notably, their longevity. An unexpected 19% of nonresectable metastatic melanoma patients are still alive after 11 years, a survival rate similar to that observed in ipilimumab-treated patients and achieved without any major (>grade 2) toxicity. Survival correlated significantly with the development of intense vaccine injection site reactions, and with blood eosinophilia after the first series of vaccinations, suggesting that prolonged survival was a consequence of DC vaccination. CONCLUSIONS: Long-term survival in advanced melanoma patients undergoing DC vaccination is similar to ipilimumab-treated patients and occurs upon induction of tumor-specific T cells, blood eosinophilia, and strong vaccine injection site reactions occurring after the initial vaccinations. TRIAL REGISTRATION: ClinicalTrials.gov NCT00053391. FUNDING: European Community, Sixth Framework Programme (Cancerimmunotherapy LSHC-CT-2006-518234; DC-THERA LSHB-CT-2004-512074), and German Research Foundation (CRC 643, C1, Z2).
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Twice-refocused stimulated echo diffusion imaging: Measuring diffusion time dependence at constant T-1 weighting - Martin, Jan; Endt, Sebastian; Wetscherek, Andreas; Kuder, Tristan Anselm; Dörfler, Arnd; Uder, Michael; Hensel, Bernhard; Laun, Frederik Bernd (Magnetic Resonance in Medicine, 2019)
Purpose Diffusion times longer than 50 ms are typically probed with stimulated-echo sequences. Varying the diffusion time in stimulated-echo sequences affects the T-1 weighting of subcompartments, complicating the analysis of diffusion time dependence. Although inversion recovery preparation could be used to change the T-1 weighting, it cannot ensure equal T-1 weighting at arbitrary mixing times. In this article, a sequence that ensures constant T-1 weighting over a wide range of diffusion times is presented. Methods The proposed sequence features 2 independent longitudinal storage periods: TM1 and TM2. Diffusion encoding is performed during TM1, effectively coupling the diffusion time and TM1. Equal T-1 weighting at arbitrary diffusion times is realized by keeping the total mixing time TM1 + TM2 constant. The sequence was compared with conventional stimulated-echo measurements of diffusion in a 2-compartment phantom consisting of distilled water and paraffinum perliquidum. Additionally, in vivo DTI of the brain was carried out for 8 healthy volunteers with diffusion times ranging from 50 to 500 ms. Results Diffusion time dependence of the axial and radial diffusivity was detected in the brain. Both sequences resulted in almost identical diffusivities in white matter. In regions containing partial volumes of gray and white matter, a dependency on T-1 weighting was observed. Conclusion In accordance with previous studies, little variance of T-1 values appeared to be present in healthy white matter. However, this is likely different in diseased tissue. Here, the proposed sequence can be effective in differentiating between diffusion time dependence and T-1 weighting effects.
CRIS-Team WoS Importer:2019-11-12

Two- to five-year follow-up of 78 patients after treatment with the Flow Redirection Endoluminal Device - Lücking, Hannes; Dörfler, Arnd; Gölitz, Philipp; Engelhorn, Tobias; Lang, Stefan; Hölter, Philip (Interventional Neuroradiology, 2019)
Background and purpose Flow-diverter stents are well-established for the treatment of cerebral aneurysms. Flow Redirection Endoluminal Device differs from other flow-diverter stents by its dual-layer design and has proved equality to other devices in numerous short-term surveys. However, follow-up data covering substantially more than one year are still limited for this device. We present our long-term experience with Flow Redirection Endoluminal Device.
CRIS-Team WoS Importer:2019-10-22

Two- to five-year follow-up of 78 patients after treatment with the Flow Redirection Endoluminal Device - Lücking, Hannes; Dörfler, Arnd; Gölitz, Philipp; Hölter, Philip; Engelhorn, Tobias; Lang, Stefan (Interventional Neuroradiology, 2020)
BACKGROUND AND PURPOSE: Flow-diverter stents are well-established for the treatment of cerebral aneurysms. Flow Redirection Endoluminal Device differs from other flow-diverter stents by its dual-layer design and has proved equality to other devices in numerous short-term surveys. However, follow-up data covering substantially more than one year are still limited for this device. We present our long-term experience with Flow Redirection Endoluminal Device. MATERIALS AND METHODS: Seventy-eight patients harboring distal internal carotid artery (91%) or vertebrobasilar (9%) cerebral aneurysms treated with Flow Redirection Endoluminal Device with or without adjunctive coiling met the inclusion criteria. All cases were evaluated for aneurysm occlusion (according to Modified Raymond Roy Classification, MRRC), for flow-diverter stents patency and configuration and for procedure- and device-related morbidity and mortality. RESULTS: Mean follow-up interval was 36.9 ± 9.5 months (<30 months: n = 18; 31-42 months: n = 31; >42 months: n = 24). Total and subtotal aneurysm occlusion after six months was assessed in 92.0% (MRRC1 = 77.3%, MRRC2 = 14.7%, MRRC3a =2.7%, MRRC3b = 4.1%) and increased to 95.9% (MRRC1 = 90.5%, MRRC2 = 5.4%, MRRC3a = 2.7%). There was one case of aneurysm growth requiring early re-treatment. Procedure-related morbidity was observed in three cases (3.8%; one transient hemiparesis, one suspected foreign-body reaction, and one micro-wire perforation). There was no procedure- or device-related mortality. In-stent stenosis due to intimal hyperplasia was observed in two cases and fish-mouthing in three cases. CONCLUSIONS: Our long-term data covering two to five years after flow diversion confirm that Flow Redirection Endoluminal Device is a safe and effective device for the treatment of cerebral aneurysms with progressive high aneurysm occlusion rates; recurrence rates were very low. Overall device-related morbidity was low and was not observed later than six months after intervention.
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Überblick über Subtypen und Therapien der akuten Mesenterialischämie - Eckhardt, Daniel; Schmid, Axel; Grützmann, Robert (Zentralblatt für Chirurgie, 2019)
CRIS-Team Scopus Importer:2019-06-28

Ultraearly assessed reperfusion status after middle cerebral artery recanalization predicting clinical outcome - Gölitz, Philipp; Mühlen, Iris; Gerner, Stefan; Knossalla, F.; Dörfler, Arnd (Acta Neurologica Scandinavica, 2018)
Objectives: Mechanical thrombectomy has high evidence in stroke therapy; however, successful recanalization guarantees not a favorable clinical outcome. We aimed to quantitatively assess the reperfusion status ultraearly after successful middle cerebral artery (MCA) recanalization to identify flow parameters that potentially allow predicting clinical outcome. Materials and Methods: Sixty-seven stroke patients with acute MCA occlusion, undergoing recanalization, were enrolled. Using parametric color coding, a post-processing algorithm, pre-, and post-interventional digital subtraction angiography series were evaluated concerning the following parameters: pre- and post-procedural cortical relative time to peak (rTTP) of MCA territory, reperfusion time, and index. Functional long-term outcome was assessed by the 90-day modified Rankin Scale score (mRS; favorable: 0-2). Results: Cortical rTTP was significantly shorter before (3.33 +/- 1.36seconds; P = .03) and after intervention (2.05 +/- 0.70seconds; P=.003) in patients with favorable clinical outcome. Additionally, age (P=.005) and initial National Institutes of Health Stroke Scale score (P = .02) were significantly different between the patients, whereas reperfusion index and time as well as initially estimated infarct size were not. In multivariate analysis, only post-procedural rTTP (P=.005) was independently associated with favorable clinical outcome. 2.29seconds for post-procedural rTTP might be a threshold to predict favorable clinical outcome. Conclusions: Ultraearly quantitative assessment of reperfusion status after successful MCA recanalization reveals post-procedural cortical rTTP as possible independent prognostic value in predicting favorable clinical outcome, even determining a threshold value might be possible. In consequence, focusing stroke therapy on microcirculatory patency could be valuable to improve outcome.
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Ultra-early Detection of Microcirculatory Injury as Predictor of Developing Delayed Cerebral Ischemia After Aneurysmal Subarachnoid Hemorrhage - Gölitz, Philipp; Rösch, Julie; Roessler, Karl; Knossalla, Frauke; Dörfler, Arnd; Hölter, Philip (Clinical Neuroradiology, 2018)
Purpose Delayed cerebral ischemia (DCI) still remains amajor complication after subarachnoid hemorrhage (SAH). The aim of our study was to evaluate whether flow analysis of admission digital subtraction angiography (DSA) using parametric color coding (PCC), apostprocessing algorithm, allows ultra-early identification of SAH patients at risk for developing subsequent symptomatic vasospasm. Methods In this study 52patients who suffered SAH from aneurysm rupture, were retrospectively enrolled. Of the patients 26 developed DCI and angiographically proven cerebral vasospasm and 26age, gender-and clinical status-matched SAH patients without DCI served as controls. Using PCC, the following flow parameters were calculated: cerebral circulation time (CirT), cortical relative time to peak (rTTP) and microvascular transit time (TT). Results Mean cerebral CirT and cortical rTTP were longer in the DCI group (6.42s +/- 1.54 and 3.16s +/- 0.86, respectively) than in the non-DCI group (5.77s +/- 1.86 and 3.11s +/- 1.41, respectively), but without statistical significance. The mean microvascular TT was statistically significantly (p = 0.04) longer in the DCI group (3.19s +/- 0.78) than in the non-DCI group (2.67s +/- 0.73). Conclusion Angiographic flow analysis might be suitable for ultra-early detection and quantitative assessment of microcirculatory injury in SAH patients, predictive of developing subsequent DCI. Prolonged microvascular TT seems to be asignificant independent factor positively associated with DCI development. Identifying SAH patients at risk for DCI ultra-early after ictus might contribute to initiate prophylactic therapies before clinical deterioration.
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Ultra-High b-Value Diffusion-Weighted Imaging-Based Abbreviated Protocols for Breast Cancer Detection - Ohlmeyer, Sabine; Laun, Frederik Bernd; Bickelhaupt, Sebastian; Palm, Theresa; Janka, Rolf Matthias; Weiland, Elisabeth; Uder, Michael; Wenkel, Evelyn (Investigative Radiology, 2021)
Objectives Contrast-enhanced (CE) magnetic resonance imaging (MRI) is the most effective imaging modality for breast cancer detection. A contrast agent-free examination technique would be desirable for breast MRI screening. The purpose of this study was to evaluate the capability to detect and characterize suspicious breast lesions with an abbreviated, non-contrast-enhanced MRI protocol featuring ultra-high b-value diffusion-weighted imaging (DWI) compared with CE images. Materials and Methods The institutional review board-approved prospective study included 127 female subjects with different clinical indications for breast MRI. Magnetic resonance imaging examinations included DWI sequences with b-values of 1500 s/mm(2) (b1500) and 2500 s/mm(2) (b2500), native T1- and T2-weighted images, and CE sequences at 1.5 T and 3 T scanners. Two reading rounds were performed, including either the b1500 or the b2500 DWI in consecutive assessment steps: (A) maximum intensity projections (MIPs) of DWI, (B) DWI and apparent diffusion coefficient maps, (C) as (B) but with additional native T1- and T2-weighted images, and (D) as (C) but with additional CE images (full-length protocol). Two readers independently determined the presence of a suspicious lesion. Histological confirmation was obtained for conspicuous lesions, whereas the full MRI data set was obtained for inconspicuous and clearly benign lesions. Statistical analysis included calculation of diagnostic accuracy and interrater agreement via the intraclass correlation coefficient. Results The cohort comprised 116 cases with BI-RADS 1 findings and 138 cases with BI-RADS >= 2 findings, including 38 histologically confirmed malignancies. For (A), breasts without pathological findings could be recognized with high diagnostic accuracy (negative predictive value, >= 97.0%; sensitivity, >= 92.1% for both readers), but with a limited specificity (>= 58.3%; positive predictive value, >= 28.6%). Within the native readings, approach (C) with b2500 performed best (negative predictive value, 99.5%; sensitivity, 97.4%; specificity, 88.4%). The intraclass correlation coefficient was between 0.683 (MIP b1500) and 0.996 (full protocol). Conclusions A native abbreviated breast MRI protocol with advanced high b-value DWI might allow nearly equivalent diagnostic accuracy as CE breast MRI and seems to be well suited for lesion detection purposes.
CRIS-Team WoS Importer:2021-10-01

Ultra-high field MRI of human hippocampi: Morphological and multiparametric differentiation of hippocampal sclerosis subtypes - Gillmann, Clarissa; Coras, Roland; Roessler, Karl; Dörfler, Arnd; Uder, Michael; Blümcke, Ingmar; Bäuerle, Tobias (PLoS ONE, 2018)
The aim of the present study is to differentiate subtypes of hippocampal sclerosis (HS) using ex vivo ultra-high field magnetic resonance imaging (MRI). Included were 14 surgically resected hippocampi of patients with medically intractable temporal lobe epilepsy. The resected hippocampi were histologically categorized into subtypes of hippocampal sclerosis (HS type 1 (n = 10), HS type 2 (n = 2) and no-HS (n = 2)) and subsequently scanned on a preclinical 7T MRI acquiring T2-weighted morphology, relaxometry and diffusion tensor imaging. On the morphological images, the pyramidal cell layer (PCL) of the hippocampus was segmented and the following parameters were derived: T2 signal intensity, T1-, T2- and T2*-relaxation times, apparent diffusion coefficient (ADC), fractional anisotropy (FA) and mean diffusivity (MD). Furthermore, the area of the PCL was determined, as well as the parameter product which refers to the widths of the PCL parallel and perpendicular to the stratum moleculare. Spearman correlation coefficient was used to demonstrate relationships between MR-parameters and type of sclerosis. In comparison to no-HS specimens, the PCL was significantly narrower in HS type 1 and HS type 2 hippocampi. This narrowing affected the entire cornu ammonis sector (CA) 1 in HS type 1, while it was limited to the upper half of CA1 in direction to CA2 in HS type 2. The parameter product median increased from 0.43 to 1.67 and 2.91 mm2 for HS type 1, HS type 2 and no-HS, respectively. Correlation coefficients were significant for the PCL parameters product (0.73), area (0.71), T2*-time (-0.67), FA (0.65) and ADC (0.55). Our initial results suggest that HS type 1, HS type 2 and no-HS subtypes can be distinguished from each other using ex vivo UHF MRI based on T2-weighted morphologic images and the assessment of the parameter product. Upon clinical translation, UHF-MRI may provide a promising technique for the preoperative differentiation of HS subtypes in patients.
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Ultra high-field SWI of the substantia nigra at 7T: reliability and consistency of the swallow-tail sign - Schmidt, Manuel; Engelhorn, Tobias; Marxreiter, Franz; Winkler, Jürgen; Lang, Stefan; Kloska, Stephan; Gölitz, Philipp; Dörfler, Arnd (BMC Neurology, 2017)
BACKGROUND: The loss of the swallow-tail sign of the substantia nigra has been proposed for diagnosis of Parkinson's disease. Aim was to evaluate, if the sign occurs consistently in healthy subjects and if it can be reliably detected with high-resolution 7T susceptibility weighted imaging (SWI). METHODS: Thirteen healthy adults received SWI at 7T. 3 neuroradiologists, who were blinded to patients' diagnosis, independently classified subjects regarding the swallow-tail sign to be present or absent. Accuracy, positive and negative predictive values (PPV and NPV) as well as inter- and intra-rater reliability and internal consistency were analyzed. RESULTS: The sign could be detected in 81% of the cases in consensus reading. Accuracy to detect the sign compared to the consensus was 100, 77 and 96% for the three readers with PPV reader 1/2/3 = 1/0.45/0.83 and NPV = 1/1/1. Inter-rater reliability was excellent (inter-class correlation coefficient = 0.844, alpha = 0.871). Intra-rater reliability was good to excellent (reader 1 R/L = 0.625/0.786; reader 2 = 0.7/0.64; reader 3 = 0.9/1). CONCLUSION: The swallow-tail sign can be reliably detected. However, our data suggest its occurrence is not consistent in healthy subjects. It may be possible that one reason is an individually variable molecular organization of nigrosome 1 so that it does not return a uniform signal in SWI.
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Ultra-low dose comprehensive cardiac CT imaging in a patient with acute myocarditis - Tröbs, Monique; Brand, Michael; Achenbach, Stephan; Marwan, Mohamed (Journal of Cardiovascular Computed Tomography, 2014)
The ability of contrast-enhanced CT to detect "late enhancement" in a fashion similar to magnetic resonance imaging has been previously reported. We report a case of acute myocarditis with coronary CT angiography as well as "late enhancement" imaging with ultra-low effective radiation dose.
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Ultrasound assessment of medial meniscal extrusion: a validation study using MRI as reference standard - Nogueira-Barbosa, Marcello H.; Gregio-Junior, Everaldo; Lorenzato, Mario M.; Guermazi, Ali; Roemer, Frank; Chagas-Neto, Francisco A.; Crema, Michel D. (American Journal of Roentgenology, 2015)
OBJECTIVE. The purpose of this article is to validate both semiquantitative and quantitative ultrasound assessment of medial meniscal extrusion using MRI assessment as the reference standard. SUBJECTS AND METHODS. Ninety-three consecutive patients with chronic knee pain referred for knee MRI were evaluated by ultrasound and MRI on the same day. Two musculoskeletal radiologists assessed meniscal extrusion on ultrasound and MRI separately and independently and graded it semiquantitatively as follows: 0 (< 2 mm), 1 (>= 2 mm and < 4 mm), and 2 (>= 4 mm). Agreement between the ultrasound and MRI evaluations was determined using weighted kappa statistics. Intraclass correlation coefficients were used to evaluate agreement using the absolute values of extrusion (quantitative assessment). We further evaluated the diagnostic performance of ultrasound for the detection of medial meniscal extrusion using MRI as the reference standard. RESULTS. For semiquantitative grading, agreement between ultrasound and MRI was moderate for reader 1 (? = 0.57) and substantial for reader 2 (? = 0.64). Substantial agreement was found for both readers (intraclass correlation coefficients, 0.73 and 0.70) when comparing quantitative assessment of meniscal extrusion between ultrasound and MRI. Ultrasound showed excellent sensitivity (95% and 96% for each reader) and good specificity (82% and 70% for each reader) in the detection of meniscal extrusion. CONCLUSION. Ultrasound assessment of meniscal extrusion is reliable and can be used for both quantitative and semiquantitative assessment, exhibiting excellent diagnostic performance for the detection of meniscal extrusion compared with MRI.
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Ultrasound Elastography of Pulmonary Lesions - A Feasibility Study - Adamietz, B. R.; Fasching, Peter; Jud, Sebastian; Schulz-Wendtland, Rüdiger; Anders, Katharina; Uder, Michael; Wüst, Wolfgang; Rauh, C.; Meier-Meitinger, M. (Ultraschall in der Medizin, 2014)
Introduction: The potential of sonography in the examination of lung tissue is extremely limited by the air-filled alveoles of the lung. Only in special circumstances like pleural adhesion lesions, atelectasis or pneumonia can lung tissue be visualized by B-mode sonography. Real-time elastography was primarily applied to detect and visualize pulmonary lesions. Methods and Patients: 8 patients with a total of 18 histologically proven metastases of the lung were included. All pulmonary lesions were detected by computed tomography. Sonographic examination was performed with a 7.5 MHz linear transducer (Acuson Antares premium edition, Siemens, Erlangen, Germany), including B-mode and real-time elastography (RTE). The mean distance between pleura and the lesions ranged from 0 to 2.5 cm. Two lesions were located in the upper right lobe, eleven lesions in the lower right and five in the lower left lobe. Results: RTE was able to detect and visualize all 18 pulmonary lesions in contrast to B-mode. The size and distance of the lesions from the pleura correlated with the CT findings. Conclusion: In contrast to B-mode sonography, RTE is able to detect and visualize peripheral, non-pleural adherent pulmonary lesions.
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Unbiased high-dimensional flow cytometry identified NK and DC immune cell signature in Luminal A-type and triple negative breast cancer - Heger, Lukas; Heidkamp, Gordon Frederik; Amon, Lukas; Nimmerjahn, Falk; Bäuerle, Tobias; Maier, Andreas; Erber, Ramona; Hartmann, Arndt; Hack, Carolin; Rübner, Matthias; Hübner, Hanna; Fasching, Peter; et al. (OncoImmunology, 2024)
Breast cancer is the most common malignancy in women worldwide and a highly heterogeneous disease. Four different subtypes are described that differ in the expression of hormone receptors as well as the growth factor receptor HER2. Treatment modalities and survival rate depend on the subtype of breast cancer. However, it is still not clear which patients benefit from immunotherapeutic approaches such as checkpoint blockade. Thus, we aimed to decipher the immune cell signature of the different breast cancer subtypes based on high-dimensional flow cytometry followed by unbiased approaches. Here, we show that the frequency of NK cells is reduced in Luminal A and B as well as triple negative breast cancer and that the phenotype of residual NK cells is changed toward regulatory CD11b−CD16− NK cells. Further, we found higher frequencies of PD-1+ CD4+ and CD8+ T cells in triple negative breast cancer. Moreover, while Luminal A-type breast cancer was enriched for CD14+ cDC2 (named type 3 DC (DC3)), CD14− cDC2 (named DC2) were more frequent in triple negative breast cancer. In contrast, HER2-enriched breast cancer did not show major alterations in the composition of the immune cell compartment in the tumor microenvironment. These findings suggest that patients with Luminal A- and B-type as well as triple negative breast cancer might benefit from immunotherapeutic approaches targeting NK cells.
CRIS-Team Scopus Importer:2024-01-12
Keywords: Breast cancer; immune cell signature; NK cells; PD-1; tumor microenvironment

Unbiased rigid registration using transfer functions - Hahn, Dieter; Hornegger, Joachim; Bautz, Werner; Kuwert, Torsten; Römer, Wolfgang (Medical Imaging 2005 - Image Processing, 2005)
The evaluation of tumor growth as regression under therapy is an important clinical issue. Rigid registration of sequentially acquired SD-images has proven its value for this purpose. Existing approaches to rigid image registration use the whole volume for the estimation of the rigid transform. Non-rigid soft tissue deformation, however, will imply a bias to the registration result, because local deformations cannot be modeled by rigid transforms. Anatomical substructures, like bones or teeth, are not affected by these deformations, but follow a rigid transform. This important observation is incorporated in the proposed registration algorithm. The selection of anatomical substructure is done by manual interaction of medical experts adjusting the transfer function of the volume rendering software. The parameters of the transfer function are used to identify the voxels that are considered for registration. A rigid transform is estimated by a quaternion gradient descent algorithm based on the intensity values of the specified tissue classes. Commonly used voxel intensity measures are adjusted to the modified registration algorithm. The contribution describes the mathematical framework of the proposed registration method and its implementation in a commercial software package. The experimental evaluation includes the discussion of different similarity measures, the comparison of the proposed method to established rigid registration techniques and the evaluation of the efficiency of the new method. We conclude with the discussion of potential medical applications of the proposed registration algorithm.

Unclear tumour of the ear lobe - Dürr, Stephan; Söder, Stephan; Rösler, Wolf; Schlechtweg, Philipp; Schick, B; Alexiou, Christoph (Laryngo-Rhino-Otologie, 2014)
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Understanding Magnetic Resonance Imaging of Knee Cartilage Repair: A Focus on Clinical Relevance - Hayashi, Daichi; Li, Xinning; Murakami, Akira M.; Roemer, Frank; Trattnig, Siegfried; Guermazi, Ali (Cartilage, 2018)
The aims of this review article are (a) to describe the principles of morphologic and compositional magnetic resonance imaging (MRI) techniques relevant for the imaging of knee cartilage repair surgery and their application to longitudinal studies and (b) to illustrate the clinical relevance of pre- and postsurgical MRI with correlation to intraoperative images. First, MRI sequences that can be applied for imaging of cartilage repair tissue in the knee are described, focusing on comparison of 2D and 3D fast spin echo and gradient recalled echo sequences. Imaging features of cartilage repair tissue are then discussed, including conventional (morphologic) MRI and compositional MRI techniques. More specifically, imaging techniques for specific cartilage repair surgery techniques as described above, as well as MRI-based semiquantitative scoring systems for the knee cartilage repair tissue-MR Observation of Cartilage Repair Tissue and Cartilage Repair OA Knee Score-are explained. Then, currently available surgical techniques are reviewed, including marrow stimulation, osteochondral autograft, osteochondral allograft, particulate cartilage allograft, autologous chondrocyte implantation, and others. Finally, ongoing research efforts and future direction of cartilage repair tissue imaging are discussed.
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Unrecognized myocardial scar in areas of increased plaque burden in patients with suspected coronary artery disease. A clinical coronary CTA and CMR imaging study - Gitsioudis, Gitsios; Kesselmann, J.; Missiou, Anna; Atsiatorme, E.; Bryant, M.; Giannitsis, E.; Kauczor, H. U.; Katus, H. A.; Korosoglou, G. (2017)
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Unruptured Intracranial Aneurysms- Pathogenesis and Individualized Management - Etminan, Nima; Dörfler, Arnd; Steinmetz, Helmuth (Deutsches Ärzteblatt international, 2020)
BACKGROUND: About 2 million adults in Germany harbor an unruptured intracranial aneurysm (IA). Rupture can lead to a life-threatening subarachnoid hemorrhage. If an IA is detected incidentally in cranial imaging, it must be decided how to proceed. METHODS: This review includes key publications that were identified by a selective search in the PubMed database using the search term "unruptured intracranial aneurysms," which was performed in July 2019, and based on information obtained from the German Federal Statistical Office on the frequency of the hospital discharge diagnosis "cerebral aneurysm," excluding the diagnosis "subarachnoid hemorrhage," in Germany from 2005 to 2017. RESULTS: The number of patients in Germany who were admitted or treated for an unruptured IA increased by a factor of 2.3 from 2005 to 2017. The average 5-year rupture risk of approximately 3% must be weighed against the approximately 4% risk associated with an endovascular or microneurosurgical treatment. This emphasizes the need for more precise data on the risk of rupture and for algorithms enabling individualized decision-making for patients with unruptured IA. Risk factors such as IA morphology, arterial hypertension, active smoking, and alcohol consumption (>150 g/week) can markedly increase the risk of rupture, which is generally relatively low. Growing aneurysms are 12 times more likely to rupture than stable ones. Follow-up imaging is thus essential whenever observation rather than intervention is chosen as the initial management. CONCLUSION: Patients with unruptured IA should be massessed and managed individually. It is also important that risk factors should be treated, if present. Eligible patients are currently being recruited for a phase III clinical trial on the efficacy of blood pressure reduction combined with acetylsalicylic acid intake to counteract inflammatory processes in the arterial wall.
CRIS-Team Scopus Importer:2020-06-05

Update cartilage imaging of the small joints: Focus on high-field MRI [Update Knorpelbildgebung der kleinen Gelenke: Fokus Hochfeld-MRT] - Heiß, Rafael; Janka, Rolf Matthias; Uder, Michael; Nagel, Armin Michael; Trattnig, S.; Roemer, Frank (Radiologe, 2019)
Background: Cartilage imaging of small joints is increasingly of interest, as early detection of cartilage damage may be relevant regarding individualized surgical therapies and long-term outcomes. Purpose: The aim of this review is to explain modern cartilage imaging of small joints with emphasis on MRI and to discuss the role of methods such as CT arthrography as well as compositional and high-field MRI. Materials and methods: A PubMed literature search was performed for the years 2008–2018. Results: Clinically relevant cartilage imaging to detect chondral damage in small joints remains challenging. Conventional MRI at 3 T can still be considered as a reference for cartilage imaging in clinical routine. In terms of sensitivity, MR arthrography (MR-A) and computed tomography arthrography (CT-A) are superior to non-arthrographic MRI at 1.5 T in the detection of chondral damage. Advanced degenerative changes of the fingers and toes are usually sufficiently characterized by conventional radiography. MRI at field strengths of 3 T and ultrahigh-field imaging at 7 T can provide additional quantifiable, functional and metabolic information. Conclusion: Standardized cartilage imaging plays an important role in clinical diagnostics in the ankle joint due to the availability of different and individualized therapeutic concepts. In contrast, cartilage imaging of other small joints as commonly performed in clinical studies has not yet become standard of care in daily clinical routine. Although individual study results are promising, additional studies with large patient collectives are needed to validate these techniques. With rapid development of new treatment concepts radiological diagnostics will play a more significant role in the diagnosis of cartilage lesions of small joints.
CRIS-Team Scopus Importer:2019-05-02
Keywords: Ankle; Glycosaminoglycans; Literature review; Magnetic resonance imaging; Wrist

Update on recent developments in imaging of inflammation in osteoarthritis: a narrative review - Hayashi, Daichi; Roemer, Frank; Jarraya, Mohamed; Guermazi, Ali (Skeletal Radiology, 2022)
Synovitis is an important component of the osteoarthritis (OA) disease process, particularly regarding the "inflammatory phenotype " of OA. Imaging plays an important role in the assessment of synovitis in OA with MRI and ultrasound being the most deployed imaging modalities. Contrast-enhanced (CE) MRI, particularly dynamic CEMRI (DCEMRI) is the ideal method for synovitis assessment, but for several reasons CEMRI is not commonly performed for OA imaging in general. Effusion-synovitis and Hoffa-synovitis are commonly used as surrogate markers of synovitis on non-contrast-enhanced (NCE) MRI and have been used in many epidemiological observational studies of knee OA. Several semiquantitative MRI scoring systems are available for the evaluation of synovitis in knee OA. Synovitis can be a target tissue for disease-modifying OA drug (DMOAD) clinical trials. Both MRI and ultrasound may be used to determine the eligibility and assess the therapeutic efficacy of DMOAD approaches. Ultrasound is mostly used for evaluation of synovitis in hand OA, while MRI is typically used for larger joints, namely knees and hips. The role of other modalities such as CT (including dual-energy CT) and nuclear medicine imaging (such as positron-emission tomography (PET) and its hybrid imaging) is limited in the context of synovitis assessment in OA. Despite research efforts to develop NCEMRI-based synovitis evaluation methods, these typically underestimate the severity of synovitis compared to CEMRI, and thus more research is needed before we can rely only on NCEMRI.
CRIS-Team WoS Importer:2023-02-03

Update: Posttreatment Imaging of the Knee after Cartilage Repair. - Heiß, Rafael; Guermazi, Ali; Janka, Rolf Matthias; Uder, Michael; Li, Xinning; Hayashi, Daichi; Roemer, Frank (Seminars in Musculoskeletal Radiology, 2022)
Focal cartilage lesions are common pathologies at the knee joint that are considered important risk factors for the premature development of osteoarthritis. A wide range of surgical options, including but not limited to marrow stimulation, osteochondral auto- and allografting, and autologous chondrocyte implantation, allows for targeted treatment of focal cartilage defects. Arthroscopy is the standard of reference for the assessment of cartilage integrity and quality before and after repair. However, deep cartilage layers, intrachondral composition, and the subchondral bone are only partially or not at all visualized with arthroscopy. In contrast, magnetic resonance imaging offers noninvasive evaluation of the cartilage repair site, the subchondral bone, and the soft tissues of the joint pre- and postsurgery. Radiologists need to be familiar with the different surgical procedures available and their characteristic postsurgical imaging appearances to assess treatment success and possible complications adequately. We provide an overview of the most commonly performed surgical procedures for cartilage repair at the knee and typical postsurgical imaging characteristics.
EVALuna2:506329

Usability of magnetic resonance images acquired at a novel low-field 0.55 T scanner for brain radiotherapy treatment planning - Grigo, Johanna; Masitho, Siti; Fautz, Hans Peter; Voigt, Raphaela; Schonath, Miriam; Oleszczuk, Annika; Uder, Michael; Heiß, Rafael; Fietkau, Rainer; Putz, Florian; Bert, Christoph (Physics and Imaging in Radiation Oncology, 2023)
Background and Purpose: Low-field magnetic resonance imaging (MRI) may offer specific advantages over high-field MRI, e.g. lower susceptibility-dependent distortions and simpler installation. The study aim was to evaluate if a novel 0.55 T MRI scanner provides sufficient image accuracy and quality for radiotherapy (RT) treatment planning. Material and methods: The geometric accuracy of images acquired at a low-field MRI scanner was evaluated in phantom measurements regarding gradient non-linearity-related distortions. Patient-induced B0-susceptibility changes were investigated via B0-field-mapping in ten volunteers. Patients were positioned in RT-setup using a 3D-printed insert for the head/neck-coil that was tested for sufficient signal-to-noise-ratio (SNR). The suitability of the MRI-system for detection of metastases was evaluated in eleven patients. In comparison to diagnostic images, acquired at ≥1.5 T, three physicians evaluated the detectability of metastases by counting them in low- and high-field-images, respectively. Results: The phantom measurements showed a high imaging fidelity after 3D-distortion-correction with (1.2 ± 0.9) mm geometric distortion in 10 cm radius from isocentre. At the edges remaining distortions were greater than at 1.5 T. The mean susceptibility-induced distortions in the head were (0.05 ± 0.05) mm and maximum 0.69 mm. SNR analysis showed that optimised positioning of RT-patients without signal loss in the head/neck-coil was possible with the RT-insert. No significant differences (p = 0.48) in detectability of metastases were found. Conclusion: The 0.55 T MRI system provided sufficiently geometrically accurate and high-resolution images that can be used for RT-planning for brain metastases. Hence, modern low-field MRI may contribute to simply access MRI for RT-planning after further investigations.
CRIS-Team Scopus Importer:2023-02-17
Keywords: Low-Field-MRI; MRI; Radiotherapy

USE OF CLINICAL AND IMAGING FEATURES OF OSTEOARTHRITIS TO PREDICT KNEE REPLACEMENT IN PERSONS WITH AND WITHOUT RADIOGRAPHIC OSTEOARTHRITIS: THE MOST STUDY - Jafarzadeh, S.; Felson, D. T.; Nevitt, M. C.; Torner, J. C.; Lewis, C. E.; Roemer, Frank; Guermazi, A.; Neogi, T. (OSTEOARTHRITIS AND CARTILAGE, 2020)
CRIS-Team WoS Importer:2020-06-02

Using automated texture features to determine the probability for masking of a tumor on mammography, but not ultrasound - Haeberle, Lothar; Hack, Carolin; Heusinger, Katharina; Wagner, Florian; Jud, Sebastian; Uder, Michael; Beckmann, Matthias; Schulz-Wendtland, Rüdiger; Wittenberg, Thomas; Fasching, Peter (European Journal of Medical Research, 2017)
BACKGROUND: Tumors in radiologically dense breast were overlooked on mammograms more often than tumors in low-density breasts. A fast reproducible and automated method of assessing percentage mammographic density (PMD) would be desirable to support decisions whether ultrasonography should be provided for women in addition to mammography in diagnostic mammography units. PMD assessment has still not been included in clinical routine work, as there are issues of interobserver variability and the procedure is quite time consuming. This study investigated whether fully automatically generated texture features of mammograms can replace time-consuming semi-automatic PMD assessment to predict a patient's risk of having an invasive breast tumor that is visible on ultrasound but masked on mammography (mammography failure). METHODS: This observational study included 1334 women with invasive breast cancer treated at a hospital-based diagnostic mammography unit. Ultrasound was available for the entire cohort as part of routine diagnosis. Computer-based threshold PMD assessments ("observed PMD") were carried out and 363 texture features were obtained from each mammogram. Several variable selection and regression techniques (univariate selection, lasso, boosting, random forest) were applied to predict PMD from the texture features. The predicted PMD values were each used as new predictor for masking in logistic regression models together with clinical predictors. These four logistic regression models with predicted PMD were compared among themselves and with a logistic regression model with observed PMD. The most accurate masking prediction was determined by cross-validation. RESULTS: About 120 of the 363 texture features were selected for predicting PMD. Density predictions with boosting were the best substitute for observed PMD to predict masking. Overall, the corresponding logistic regression model performed better (cross-validated AUC, 0.747) than one without mammographic density (0.734), but less well than the one with the observed PMD (0.753). However, in patients with an assigned mammography failure risk >10%, covering about half of all masked tumors, the boosting-based model performed at least as accurately as the original PMD model. CONCLUSION: Automatically generated texture features can replace semi-automatically determined PMD in a prediction model for mammography failure, such that more than 50% of masked tumors could be discovered.
UnivIS-Import:2017-12-18:Pub.2017.tech.IMMD.IMMD9.usinga
Keywords: Mammographic density; Mammography screening; Masking; Risk prediction; Sensitivity; Texture analysis; Variable selection

Using Cartilage MRI T2-Mapping to Analyze Early Cartilage Degeneration in the Knee Joint of Young Professional Soccer Players - Waldenmeier, Leonie; Evers, Christoph; Uder, Michael; Janka, Rolf Matthias; Hennig, Friedrich; Pachowsky, Milena; Welsch, Götz Hannes (Cartilage, 2019)
Objective: To evaluate and characterize the appearance of articular cartilage in the tibiofemoral joint of young professional soccer players using T2-relaxation time evaluation on magnetic resonance imaging (MRI). Design: In this study, we included 57 male adolescents from the youth academy of a professional soccer team. The MRI scans were acquired of the knee joint of the supporting leg. An “early unloading” (minute 0) and “late unloading” (minute 28) T2-sequence was included in the set of images. Quantitative T2-analysis was performed in the femorotibial joint cartilage in 4 slices with each 10 regions of interest (ROIs). Statistical evaluation, using Wilcoxon signed-rank tests, was primarily performed to compare the T2 values of the “early unloading” and “late unloading.” Results: When comparing “early unloading” with “late unloading,” our findings showed a significant increase of T2-relaxation times in the weightbearing femoral cartilage of the medial (P < 0.001) and lateral (P < 0.001) compartment of the knee and in the tibial cartilage of the medial compartment (P < 0.001). Conclusion: In this study, alterations of the cartilage were found with a maximum in the medial condyle where the biomechanical load of the knee joint is highest, as well as where most of the chronic cartilage lesions occur. To avoid chronic damage, special focus should be laid on this region.
CRIS-Team Scopus Importer:2019-07-02
Keywords: articular cartilage; biomechanics; knee; magnetic resonance imaging; sports injury

UTE-T2* versus conventional T2* mapping to assess posterior cruciate ligament ultrastructure and integrity-an in-situ study - Wilms, Lena Marie; Radke, Karl Ludger; Latz, David; Thiel, Thomas Andreas; Frenken, Miriam; Kamp, Benedikt; Filler, Timm Joachim; Nagel, Armin Michael; Müller-Lutz, Anja; Abrar, Daniel Benjamin; Nebelung, Sven (Quantitative Imaging in Medicine and Surgery, 2022)
Background: Clinical-standard morphologic magnetic resonance imaging (MRI) is limited in the refined diagnosis of posterior cruciate ligament (PCL) injuries. Quantitative MRI sequences such as ultrashort echo-time (UTE)-T2* mapping or conventional T2* mapping have been theorized to quantify ligament (ultra-) structure and integrity beyond morphology. This study evaluates their diagnostic potential in identifying and differentiating partial and complete PCL injuries in a standardized graded injury model. Methods: Ten human cadaveric knee joint specimens were imaged on a clinical 3.0 T MRI scanner using morphologic, conventional T2* mapping, and UTE-T2* mapping sequences before and after standardized arthroscopic partial and complete PCL transection. Following manual segmentation, quantitative T2* and underlying texture features (i.e., energy, homogeneity, and variance) were analyzed for each specimen and PCL condition, both for the entire PCL and its subregions. For statistical analysis, Friedman's test followed by Dunn's multiple comparison test was used against the level of significance of P≤0.01. Results: For the entire PCL, T2* was significantly increased as a function of injury when acquired with the UTE-T2* sequence [entire PCL: 11.1±3.1 ms (intact); 10.9±4.6 ms (partial); 14.3±4.9 ms (complete); P<0.001], but not when acquired with the conventional T2* sequence [entire PCL: 10.0±3.2 ms (intact); 11.4±6.2 ms (partial); 15.5±7.8 ms (complete); P=0.046]. The PCL subregions and texture variables showed variable changes indicative of injury-associated disorganization. Conclusions: In contrast to the conventional T2* mapping, UTE-T2* mapping is more receptive in the detection of structural damage of the PCL and allows quantitative assessment of ligament (ultra-)structure and integrity that may help to improve diagnostic differentiation of distinct injury states. Once further substantiated beyond the in-situ setting, UTE-T2* mapping may refine diagnostic evaluation of PCL injuries and -possibly- monitor ligament healing, ageing, degeneration, and inflammation.
CRIS-Team Scopus Importer:2022-07-15
Keywords: knee joint instability; Magnetic resonance imaging (MRI); posterior cruciate ligament (PCL); quantitative imaging; ultrashort echo-time (UTE)-T2*

Validation of automatic MRI hippocampal subfield segmentation by histopathological evaluation in patients with temporal lobe epilepsy - Menzler, Katja; Hamer, Hajo; Mross, Peter; Rosenow, Felix; Deichmann, Ralf; Wagner, Marlies; Gracien, René Maxime; Dörfler, Arnd; Blümcke, Ingmar; Coras, Roland; Belke, Marcus; Knake, Susanne (Seizure-European Journal of Epilepsy, 2021)
Objective: The present study validates the results of automated hippocampal subfield segmentation with histopathology in epilepsy patients undergoing epilepsy surgery. Methods: We performed an automated hippocampal subfield segmentation on presurgical three-dimensional, T1-weighted magnetization Prepared Rapid Acquisition of Gradient Echoes Magnetic Resonance Imaging (MRI) data of 25 patients with unilateral mesial temporal lobe epilepsy due to hippocampal sclerosis (HS), using Freesurfer Version 6.0. The resulting volumes of cornu ammonis (CA) subfields CA1, CA2/3, CA4 and the dentate gyrus (DG) were compared to the histopathological cell count. Results: We found a significant correlation between histopathology in subregion CA2 and automated segmentation of subregion CA1 (p = 0.0062), CA2/3 (p = 0.004), CA4 (p = 0.0062) and the DG (p = 0.0054), between histopathology in CA3 and automated segmentation of CA1 (p = 0.0132), CA2/3 (p = 0.0004), CA4 (p = 0.0032) and the DG (p = 0.0037), as well as between histopathology in the DG and automated segmentation of CA1 (p = 0.0115), CA2/3 (p < 0.0001), CA4 (p < 0.0001) and the DG (p = 0.0001). The histopathological finding of HS type 1 could correctly be classified in all cases on MRI. Significance: The present study shows significant correlations between histopathological evaluation and results of the automated segmentation of the hippocampus, thereby validating the automated segmentation method. As the differential involvement of different hippocampal subfields may be associated with clinical parameters and the outcome after epilepsy surgery, the automated segmentation is also promising for prognostic purposes.
CRIS-Team Scopus Importer:2021-04-02
Keywords: Automated segmentation; Hippocampal subfields; Mesiotemporal sclerosis; Mri

Value of Flat-detector Computed Tomography Angiography with Intravenous Contrast Media Injection in the Evaluation and Treatment of Acutely Ruptured Aneurysms of the AcomA complex: A Single Center Experience in 15 Cases - Rösch, Julie; Lang, Stefan; Gölitz, Philipp; Kallmünzer, Bernd; Roessler, Karl; Dörfler, Arnd; Struffert, Tobias (Clinical Neuroradiology, 2018)
Objective To illustrate the added value of flat-detector computed tomography angiography with intravenous contrast media injection (intravenous FDCTA) in the evaluation of complex A1/A2/AcomA aneurysms. Patients and Methods We retrospectively reviewed 15patients with ruptured aneurysms. In each patient, an intravenous FDCTA was performed and its diagnostic value investigated. Results In all patients, FDCTA contributed relevant additional information concerning the anatomy of the A1/A2/AcomA complex and the relationship of the aneurysm neck to these vascular structures, which could not be gained by 2D- and 3D-DSA, and changed the management in 33% of the patients (5 out of 15). In an additional 5cases, knowledge of the detailed anatomy was helpful to plan the exact stent position. Conclusion In case of complex A1/A2/AcomA aneurysms, intravenous FDCTA is an effective option to visualize the exact location of the aneurysm neck and the relationship between the aneurysm and the adjacent vessels. Thus, it is of significant added value in the precise planning of atherapeutic strategy.
EVALuna2:34934

Variable White Matter Atrophy and Intellectual Development in a Family With X-linked Creatine Transporter Deficiency Despite Genotypic Homogeneity - Heussinger, Nicole; Saake, Marc; Mennecke, Angelika; Dörr, Helmuth-Günther; Trollmann, Regina (Pediatric Neurology, 2017)
The X-linked creatine transporter deficiency (CRTD) caused by an SLC6A8 mutation represents the second most common cause of X-linked intellectual disability. The clinical phenotype ranges from mild to severe intellectual disability, epilepsy, short stature, poor language skills, and autism spectrum disorders. The objective of this study was to investigate phenotypic variability in the context of genotype, cerebral creatine concentration, and volumetric analysis in a family with CRTD.The clinical phenotype and manifestations of epilepsy were assessed in a Caucasian family with CRTD. DNA sequencing and creatine metabolism analysis confirmed the diagnosis. Cerebral magnetic resonance imaging (cMRI) with voxel-based morphometry and magnetic resonance spectroscopy was performed in all family members.An SLC6A8 missense mutation (c.1169C>T; p.Pro390Leu, exon 8) was detected in four of five individuals. Both male siblings were hemizygous, the mother and the affected sister heterozygous for the mutation. Structural cMRI was normal, whereas voxel-based morphometry analysis showed reduced white matter volume below the first percentile of the reference population of 290 subjects in the more severely affected boy compared with family members and controls. Normalized creatine concentration differed significantly between the individuals (P < 0.005).There is a broad phenotypic variability in CRTD even in family members with the same mutation. Differences in mental development could be related to atrophy of the subcortical white matter.
EVALuna2:14646

Variation in cartilage T2 and T2* mapping of the wrist: a comparison between 3- and 7-T MRI - Heiß, Rafael; Weber, Marc André; Balbach, Eva; Hinsen, Maximilian; Geißler, Frederik; Nagel, Armin Michael; Ladd, Mark E.; Arkudas, Andreas; Horch, Raymund E.; Gall, Christine; Uder, Michael; Roemer, Frank (European Radiology Experimental, 2023)
Background: To analyze regional variations in T2 and T2* relaxation times in wrist joint cartilage and the triangular fibrocartilage complex (TFCC) at 3 and 7 T and to compare values between field strengths. Methods: Twenty-five healthy controls and 25 patients with chronic wrist pain were examined at 3 and 7 T on the same day using T2- and T2*-weighted sequences. Six different regions of interest (ROIs) were evaluated for cartilage and 3 ROIs were evaluated at the TFCC based on manual segmentation. Paired t-tests were used to compare T2 and T2* values between field strengths and between different ROIs. Spearman’s rank correlation was calculated to assess correlations between T2 and T2* time values at 3 and 7 T. Results: T2 and T2* time values of the cartilage differed significantly between 3 and 7 T for all ROIs (p ≤ 0.045), with one exception: at the distal lunate, no significant differences in T2 values were observed between field strengths. T2* values differed significantly between 3 and 7 T for all ROIs of the TFCC (p ≤ 0.001). Spearman’s rank correlation between 3 and 7 T ranged from 0.03 to 0.62 for T2 values and from 0.01 to 0.48 for T2* values. T2 and T2* values for cartilage varied across anatomic locations in healthy controls at both 3 and 7 T. Conclusion: Quantitative results of T2 and T2* mapping at the wrist differ between field strengths, with poor correlation between 3 and 7 T. Local variations in cartilage T2 and T2* values are observed in healthy individuals. Relevance statement: T2 and T2* mapping are feasible for compositional imaging of the TFCC and the cartilage at the wrist at both 3 and 7 T, but the clinical interpretation remains challenging due to differences between field strengths and variations between anatomic locations. Key points: •Field strength and anatomic locations influence T2 and T2* values at the wrist. •T2 and T2* values have a poor correlation between 3 and 7 T. •Local reference values are needed for each anatomic location for reliable interpretation. Graphical Abstract: [Figure not available: see fulltext.]
CRIS-Team Scopus Importer:2023-12-22
Keywords: Cartilage (articular); Image processing (computer-assisted); Magnetic resonance imaging; Triangular fibrocartilage; Wrist joint

Variation of membrane particle–bound CD133 in cerebrospinal fluid of patients with subarachnoid and intracerebral hemorrhage - Bobinger, Tobias; Röder, Sebastian; Sprügel, Maximilian; Fröhlich, Kilian; Beuscher, Vanessa; Hölter, Philip; Lücking, Hannes; Corbeil, Denis; Huttner, Hagen (Journal of Neurosurgery, 2021)
OBJECTIVE Previous studies have demonstrated that human CSF contains membrane particles carrying the stem cell antigenic marker CD133 (prominin-1). Here, the authors analyzed the variation of the amount of these CD133-positive particles in the CSF of patients with subarachnoid hemorrhage (SAH) and intracerebral hemorrhage (ICH). METHODS Consecutive CSF samples from 47 patients with SAH or ICH were compared to 14 healthy control patients. After differential ultracentrifugation of CSF, the membrane particle fraction was separated on gel electrophoresis and its CD133 content was probed by immunoblotting using the mouse monoclonal antibody 80B258 directed against human CD133. The antigen-antibody complexes were detected by chemiluminescence reagents and quantified using human Caco-2 cell extract as positive control with a standardized curve. RESULTS As compared to healthy controls (6.3 ± 0.5 ng of bound CD133 antibody; n = 14), the amount of membrane particle–associated CD133 immunoreactivities was significantly elevated in patients with SAH and ICH (38.2 ± 6.6 ng and 61.3 ± 11.0 ng [p < 0.001] for SAH [n = 18] and ICH [n = 29], respectively). In both groups the CD133 level dropped during the first 7 days (i.e., day 5–7: SAH group, 24.6 ± 10.1 ng [p = 0.06]; ICH group, 25.0 ± 4.8 ng [p = 0.002]). Whereas changes in the amount of CD133-positive membrane particles between admission and day 5–7 were not associated with clinical outcomes in patients with ICH (modified Rankin Scale [mRS] scores 0–3, −30.9 ± 12.8 ng vs mRS scores 4–6, −21.8 ± 10.7 ng; p = 0.239), persistent elevation of CD133 in patients with SAH was related to impaired functional outcome 3 months after ictus (mRS scores 0–2, −29.9 ± 8.1 ng vs mRS scores 3–6, 7.6 ± 20.3 ng; p = 0.027). These data are expressed as the mean ± standard error of the mean (SEM). CONCLUSIONS Levels of membrane particle–associated CD133 in the CSF of patients with SAH and ICH are significantly increased in comparison to healthy patients, and they decline during the hospital stay. Specifically, the persistent elevation of CD133-positive membrane particles within the first week may represent a possible surrogate measure for impaired functional outcome in patients with SAH.
CRIS-Team Scopus Importer:2021-04-09
Keywords: CD133; Intracerebral hemorrhage; Membrane particles; Prominin-1; Stem cells; Subarachnoid hemorrhage; Vascular disorders

Varus thrust during walking and the risk of incident and worsening medial tibiofemoral MRI lesions: the Multicenter Osteoarthritis Study - Wink, A. E.; Gross, K. D.; Brown, C. A.; Guermazi, Ali; Roemer, Frank; Niu, J.; Torner, J.; Lewis, C. E.; Nevitt, M. C.; Tolstykh, I.; Sharma, Leena; Felson, D. T. (Osteoarthritis and Cartilage, 2017)
OBJECTIVE: To determine the association of varus thrust during walking to incident and worsening medial tibiofemoral cartilage damage and bone marrow lesions (BMLs) over 2 years in older adults with or at risk for osteoarthritis (OA). METHOD: Subjects from the Multicenter Osteoarthritis Study (MOST) were studied. Varus thrust was visually assessed from high-speed videos of forward walking trials. Baseline and two-year MRIs were acquired from one knee per subject and read for cartilage loss and BMLs. Logistic regression with generalized estimating equations was used to estimate the odds of incident and worsening cartilage loss and BMLs, adjusting for age, sex, race, body mass index (BMI), and clinic site. The analysis was repeated stratified by varus, neutral, and valgus alignment. RESULTS: 1007 participants contributed one knee each. Varus thrust was observed in 29.9% of knees. Knees with thrust had 2.17 [95% CI: 1.51, 3.11] times the odds of incident medial BML, 2.51 [1.85, 3.40] times the odds of worsening medial BML, and 1.85 [1.35, 2.55] times the odds of worsening medial cartilage loss. When stratified by alignment, varus knees also had significantly increased odds of these outcomes. CONCLUSION: Varus thrust observed during walking is associated with increased odds of incident and worsening medial BMLs and worsening medial cartilage loss. Increased odds of these outcomes persist in varus-aligned knees.
EVALuna2:36271

Vascular and renal hemodynamic changes after renal denervation - Ott, Christian; Janka, Rolf Matthias; Schmid, Axel; Titze, Stephanie; Ditting, Tilmann; Sobotka, Paul A.; Veelken, Roland; Uder, Michael; Schmieder, Roland (Clinical Journal of the American Society of Nephrology, 2013)
Background and objectives Renal denervation (RDN) has been shown to be effective in reducing BP in treatmentresistant hypertension. Measurement of the renal and sympathetic activity revealed a decrease in sympathetic drive to the kidney and small resistance vessels after RDN. However, the consequences on renal perfusion and renal vascular resistance (RVR), as well as central hemodynamics, are unknown. Design, setting, participants, & measurements Nineteen patients with treatment-resistant hypertension (office BP140/90mmHg, despite at least three antihypertensive drugs [including a diuretic], and diagnosis confirmed by 24-hour ambulatory BPmonitoring) underwent RDNbetween January andOctober 2011. Renal perfusion and RVR were noninvasively assessed by magnetic resonance imaging with arterial spin labeling, and renal function was assessed by estimating GFR before (day 21), after (day +1), and again after 3 months of RDN. Central hemodynamics was assessed using pulse wave analysis at day 21 and after 6 months of RDN. Results Peripheral office BP (systolic, 158±26 versus 142±23mmHg, P=0.002; diastolic, 83±13 versus 76±9mmHg, P=0.02) and mean systolic 24-hour ambulatory BP (159±17 versus 152±17 mmHg, P=0.02) were significantly reduced 6 months after RDN. Renal perfusion was not statistically different between day 21 and day +1 (256.8 [interquartile range (IQR), 241-278] versus 263.4 [IQR, 252-277] ml/min per 100 g; P=0.17) as well as after 3 months (256.8 [IQR, 241-278] versus 261.2 [IQR, 240-285] ml/min per 100 g; P=0.27) after RDN. RVR dropped (432.1 [IQR, 359-525] versus 390.6 [IQR, 338-461] AU; P=0.02), whereas renal function was not statistically different at any time point. Central systolic BP (145±31 versus 131628 mmHg; P=0.009), diastolic BP (85±18 versus 80±14 mmHg; P=0.03), and central pulse pressure (61±18 versus 52±18 mmHg; P=0.02) were significantly reduced 6 months after RDN. Central augmentation index (24±8 versus 20±8%; P=0.02) was decreased 6 months after RDN. Conclusion The data indicate that RDN significantly reduced peripheral and central BP. Despite reduced systemic BP, renal perfusion and function did not change after RDN. © 2013 by the American Society of Nephrology.
CRIS-Team Scopus Importer:2023-03-08

Vascular architecture mapping for early detection of glioblastoma recurrence - Stadlbauer, Andreas; Eyüpoglu, Ilker Yasin; Buchfelder, Michael; Zimmermann, Max; Dörfler, Arnd; Heinz, Gertraud; Oberndorfer, Stefan (Neurosurgical Focus, 2019)
OBJECTIVE: Treatment failure and inevitable tumor recurrence are the main reasons for the poor prognosis of glioblastoma (GB). Gross-total resection at repeat craniotomy for GB recurrence improves patient overall survival but requires early and reliable detection. It is known, however, that even advanced MRI approaches have limited diagnostic performance for distinguishing tumor progression from pseudoprogression. The novel MRI technique of vascular architectural mapping (VAM) provides deeper insight into tumor microvascularity and neovascularization. In this study the authors evaluated the usefulness of VAM for the monitoring of GB patients and quantitatively analyzed the features of neovascularization of early- and progressed-stage GB recurrence. METHODS: In total, a group of 115 GB patients who received overall 374 follow-up MRI examinations after standard treatment were retrospectively evaluated in this study. The clinical routine MRI (cMRI) protocol at 3 Tesla was extended with the authors' experimental VAM approach, requiring 2 minutes of extra time for data acquisition. Custom-made MATLAB software was used for calculation of imaging biomarker maps of macrovascular perfusion from perfusion cMRI as well as of microvascular perfusion and architecture from VAM data. Additionally, cMRI data were analyzed by two board-certified radiologists in consensus. Statistical procedures included receiver operating characteristic (ROC) analysis to determine diagnostic performances for GB recurrence detection. RESULTS: Overall, cMRI showed GB recurrence in 89 patients, and in 28 of these patients recurrence was detected earlier with VAM data, by 1 (20 patients) or 2 (8 patients) follow-up examinations, than with cMRI data. The mean time difference between recurrence detection with VAM and cMRI data was 147 days. During this time period the mean tumor volume increased significantly (p < 0.001) from 9.7 to 26.8 cm3. Quantitative analysis of imaging biomarkers demonstrated microvascular but no macrovascular hyperperfusion in early GB recurrence. Therefore, ROC analysis revealed superior diagnostic performance for VAM compared with cMRI. CONCLUSIONS: This study demonstrated that the targeted assessment of microvascular features using the VAM technique provided valuable information about early neovascularization activity in recurrent GB that is complementary to perfusion cMRI and may be helpful for earlier and more precise monitoring of patients suffering from GB. This VAM approach is compatible with existing cMRI protocols. Prospective clinical trials are necessary to investigate the clinical usefulness and potential benefit of increased overall survival with the use of VAM in patients with recurrent GB.
CRIS-Team Scopus Importer:2019-12-13
Keywords: AUC = area under the ROC curve; CA = contrast agent; CBV = cerebral blood volume; CE = contrast enhanced; cMRI = clinical routine MRI; cNAWM = contralateral normal appearing white brain matter; DSC = dynamic susceptibility contrast; EPI = echo-planar imaging; FN = false negative; FP = false positive; GB = glioblastoma; GE = gradient echo; glioblastoma; MRI; MTI = microvessel type indicator; MVD = microvessel density; neovascularization; OS = overall survival; RANO = Response Assessment in Neuro-Oncology; recurrence; ROC = receiver operating characteristic; ROI = region of interest; SE = spin echo; T1W = T1 weighted; TN = true negative; TP = true positive; VAM = vascular architectural mapping; vascular architecture; VHL = vascular hysteresis loop; VSI = vessel size index; µCBV = microvascular CBV

Vascular Hysteresis Loops and Vascular Architecture Mapping in Patients with Glioblastoma treated with Antiangiogenic Therapy - Stadlbauer, Andreas; Zimmermann, Max; Oberndorfer, Stefan; Dörfler, Arnd; Buchfelder, Michael; Heinz, Gertraud; Roessler, Karl (Scientific Reports, 2017)
In this study, we investigated the variability of vascular hysteresis loop (VHL) shapes and the spatial heterogeneity of neovascularization and microvascular alterations using vascular architecture mapping (VAM) in patients with recurrent glioblastoma during bevacizumab mono-therapy. VAM data were acquired in 13 patients suffering from recurrent glioblastoma prior to and 3 months after bevacizumab treatment onset using a dual contrast agent injections approach as part of routine MRI. Two patients were additionally examined after the first cycle of bevacizumab to check for early treatment response. VHLs were evaluated as biomarker maps of neovascularization activity: microvessel type indicator (MTI) and curvature (Curv) of the VHL-long-axis. Early response to bevacizumab was dominated by reduction of smaller microvasculature (around 10 µm). In the 3-month follow-up, responding tumors additionally showed a reduction in larger microvasculature (>20 µm). VAM biomarker images revealed spatially heterogeneous microvascular alterations during bevacizumab treatment. Responding, non-responding, progressive, and remote-progressive tumor areas were observed. MTI may be useful to predict responding and non-responding tumor regions, and Curv to assess severity of vasogenic edema. Analysis of VHLs in combination with VAM biomarkers may lead to a new perspective on investigating the spatial heterogeneity of neovascularization and microvascular alterations in glioblastoma during antiangiogenic therapy.
EVALuna2:33144

Vascularization of the Arteriovenous Loop in a Rat Isolation Chamber Model-Quantification of Hypoxia and Evaluation of Its Effects - Yuan, Quan; Arkudas, Andreas; Horch, Raymund E.; Hammon, Matthias; Bleiziffer, Oliver; Uder, Michael; Seuß, Hannes (Tissue Engineering: Parts A, B, and C, 2017)
The aim of this study was to analyze the three-dimensional distribution of hypoxia in the arteriovenous (AV) loop model in rats, by examining the distribution of hypoxia-inducible factor-1 alpha (HIF-1?).AV loops were created from the femoral artery and vein of male Lewis rats and an interpositional graft from the contralateral femoral vein. This AV fistula was embedded in a fibrin-filled isolation chamber and subcutaneously implanted into the thigh. The specimens were harvested after 7 days (n = 4), 10 days (n = 5), and 14 days (n = 4). The fibrin clots were stained for lectin, HIF-1?, and ectodysplasin 1 (ED1). The distribution of positive and negative cells was analyzed in three dimensions and at different points in time.The HIF-1?-positive rate increased from the proximity of the central vessel to the distant regions. From day 7 to 10, we noted a decrease in the HIF-1?-positive rate in the proximity of the vessels and an increase in the periphery. A global decrease in positive cells was seen at day 14. HIF-1? and macrophage (ED1) double staining indicated that macrophages accounted for a significant fraction of the cells. Double staining for endothelium (with lectin) demonstrated that no HIF-1? was detectable in well-vascularized areas.In the AV loop model, the HIF-1?-positive cell distribution is highly related to the vascularization process. The onset of rapid vessel outgrowth follows the increase of the HIF-1? rate closely, indicating that HIF-1? may be a driving force for vascularization.
EVALuna2:14719

Vasospasm in intracerebral hemorrhage with ventricular involvement: a prospective pilot transcranial Doppler sonography study - Kiphuth, Ines C.; Huttner, Hagen; Breuer, Lorenz; Engelhorn, Tobias; Schwab, Stefan; Köhrmann, Martin (Cerebrovascular Diseases, 2011)
Cerebral vasospasm (VSP) is a common complication after subarachnoid hemorrhage (SAH), but has rarely been reported after intracerebral hemorrhage (ICH) without subarachnoidal bleeding. The underlying pathophysiological mechanism is mainly mediated by circulating heme products within the cerebrospinal fluid, and thus patients with ICH and ventricular involvement (IVH) may also be in danger of developing VSP. The incidence and role of VSP in IVH, however, have not been systematically studied.We prospectively enrolled 115 patients with ICH with or without IVH into the study between April 2009 and April 2010. All patients received serial extracranial and transcranial Doppler sonography (TCD) at baseline, on days 3-5 and 7-9 to detect and monitor VSP. In addition, CT scans taken on admission, after 24 h and before discharge were evaluated for the occurrence of delayed cerebral ischemia.Three out of 53 patients (5.7%) with IVH showed a significant elevation of flow velocities over the examined timeframe. One of these patients developed severe VSP resulting in secondary ischemic infarction. None of the ICH patients without IVH showed significantly elevated flow velocities or secondary infarction.Cerebral VSP with secondary infarction may occur in patients with spontaneous IVH, though far less frequently than in SAH; thus, systematic screening of all patients with IVH may not be warranted. However, serial TCD should be considered in patients with secondary clinical worsening or extensive IVH.
EVALuna2:21961

Verbesserung der Deep Learning basierten Autodetektion von Hirnmetastasen durch Integration von MRT-Voraufnahmen - Huang, Yixing; Bert, Christoph; Sommer, Philipp; Frey, Benjamin; Gaipl, Udo; Distel, Luitpold; Weissmann, Thomas; Uder, Michael; Schmidt, Manuel; Dörfler, Arnd; Maier, Andreas; Fietkau, Rainer; et al. (Strahlentherapie und Onkologie, 2022)
Keywords: Deep learning; brain metastasis

Vertebral body fractures of unknown origin in cancer patients receiving MDCT: reporting by radiologists and awareness by clinicians - Wild, Melanie; Dankerl, Peter; Hammon, Matthias; Uder, Michael; Janka, Rolf Matthias (SpringerPlus, 2016)
To evaluate prevalence, radiological reporting and clinical management of pathologic vertebral body fractures (VBFs) of unknown origin in cancer patients receiving computed tomography (CT) examinations.We investigated all CT examinations (over 1 year) of male and female patients with an underlying malignancy and an increased risk of osteoporosis (age 55-79 years) for the presence of VBFs. We evaluated midline sagittal CT-reformations of the spine for prevalence, fracture type, severity and location, the accuracy and style of radiological reporting, subsequent clinical management and documentation in hospital discharge letters.848 patients were investigated. We found 143 VBFs in 94 (11 %) patients. 6, 49, and 45 % were grade 1, grade 2, and grade 3 fractures, respectively, while 20, 66, and 14 % were wedge, biconcave and crush fractures, respectively. 32 (34 %) radiological reports correctly classified VBFs as fractures, 25 (27 %) reports recognized VBFs, but did not type them, and VBFs were not described in 37 (39 %) reports. In 3 (3 %) patients further clinical work-up of VBFs was performed, while only 8 (9 %) hospital discharge letters contained the information of the presence of pathologic VBFs of unknown origin.VBFs of unknown origin appear frequently in cancer patients, however, clinical management and documentation was found in only few cases. Moreover, especially in cancer patients consistent radiological reporting of VBFs seems important, as aetiology of VBFs could be from osteoporosis, disease progression or oncological therapy, however, reporting is still performed inconsistently.
EVALuna2:14589

Vertebral metastases of urogenital carcinomas : Diagnosis and conservative therapy - Keck, Bastian; Hammon, Matthias; Uder, Michael; Huber, J.; Goebell, Peter; Kunath, F.; Wullich, Bernd; Richter, R. H. (Urologe, 2016)
The high incidence of bone metastases of urologic neoplasms and their morbidity, especially of vertebral metastases, requires exact diagnosis and consequent therapy. Conventional radiography plays an important role in the diagnosis of symptomatic bone lesions. Computed tomography can evaluate the stability of metastatic lesions and is indispensable for therapy planning. MRI and PET-CT have the highest diagnostic accuracy for the detection of bone metastases and MRI can evaluate their intra- and extraosseus components. PET-CT, PET-MRI, or SPECT-CT in combination with specific tracers - due to their high specificity and sensitivity - have the potential to replace conventional methods in the future. Conservative treatment basically consists of analgesic therapy, the administration of calcium and vitamin D3 and bisphosphonates or inhibitors of RANKL (denosumab). Moreover radium-223-dichloride can improve overall survival and the time to the first symptomatic skeletal event in castration-resistant prostate cancer patients with bone metastases.
EVALuna2:14491

VEXAS syndrome mimicking lupus-like disease - Valor-Mendez, Larissa; Sticherling, Michael; Zeschick, Martin; Atreya, Raja; Schmidt, Daniela; Waldfahrer, Frank; Saake, Marc; Hüffmeier, Ulrike; Schett, Georg; Rech, Jürgen (Rheumatology, 2023)
CRIS-Team WoS Importer:2023-03-17

Virtual Computed Tomography Colonography: Evaluation of 2D and Virtual 3D Image Quality of Sub-mSv Examinations Enabled by Third-generation Dual Source Scanner Featuring Tin Filtering - Seuß, Hannes; Janka, Rolf Matthias; Hammon, Matthias; Uder, Michael; Dankerl, Peter; Cavallaro, Alexander Josef (Academic Radiology, 2018)
RATIONALE AND OBJECTIVES: To evaluate two- and three-dimensional (2D and 3D) image quality of sub-milliSievert (mSv) computed tomography (CT) colonography utilizing a third-generation dual source CT scanner featuring a tin filter. METHODS: We retrospectively evaluated 26 consecutive patients who underwent third-generation dual source CT colonography, nine with the standard-dose clinical-scan protocol (SDP) and 17 with a low-dose protocol (LDP) featuring a tin filter. Radiation dose was evaluated by volume computed tomography dose index (CTDIvol), dose length product (DLP), effective dose (E), and size-specific dose estimate. Objective image quality was evaluated utilizing signal-to-noise ratio (SNR) derived from standardized placed regions of interest on the transverse 2D images and the ratio of SNR/CTDIvol (normalized SNR). Two radiologists in consensus assessed subjective image quality of the virtual 3D images. RESULTS: There were no significant differences in subjective image quality (P = .661). All examinations were rated "excellent" or "good" for diagnostic confidence. The mean total for DLP/E was 143.4 ± 29.8 mGy/3.00 ± 0.40 mSv in the SDP and therefore significantly higher than in the LDP with 36.9 ± 8.7 mGy/0.75 ± 0.16 mSv (P < .001). The SNR was 8.9 ± 2.1 in the SDP and 4.9 ± 0.8 in the LDP. CONCLUSIONS: Third-generation dual source CT featuring a tin filter enables consistent sub-mSv colonography without substantially impairing image quality.
EVALuna2:34692

"Virtual stent" - clinical evaluation and user experience of on-the-fly stent simulation in treatment of cerebral aneurysms - Lücking, Hannes; Birkhold, Annette; Hölter, Philip; Lang, Stefan; Gölitz, Philipp; Schmidt, Manuel; Mrochen, Anne; Brandner, Sebastian; Dörfler, Arnd (Interventional Neuroradiology, 2021)
Background Predicting final stent position can be challenging when treating cerebral aneurysms. Third-Party software proved helpful in selecting proper stents in treatment planning. Recent angiographic systems provide basic stent simulation capabilities integrated in the post-processing software to simulate stent position. Goal of this analysis was to evaluate the simulation process and correlation with definite stent position. Materials and Methods Thirty-three datasets with fusiform (n = 10) and saccular (n = 23) aneurysms, treated with stent or flow-diverter, were processed. A "virtual stent" of the same (nominal) size was simulated and its position was compared to the treatment result. Simulated length was rated in five grades (too short, shorter, equal, longer, too long), with regard to side-branches, anchoring zone etc. Simulation quality (centerline recognition/adherence to vessel margins) was rated in three grades (no, minor or major corrections required). Results Simulation was successful in 32/33 cases (97%), with one abortive attempt (3%). In 27/33 simulations (82%), there was no need for centerline refinement. Minor corrections were necessary in four and major corrections in two cases. Simulated nominal length was rated "equal" in 14/33 (42%) cases and "shorter" or "longer" - but within acceptable range - in each 9/33 (27%) cases. Conclusion Basic stent simulation tools available with genuine angiographic workplace software can provide good simulation capabilities without need for third-party equipment. They can facilitate treatment planning and help to avoid shortage of devices. Yet, lack of calculation of foreshortening in large vessel diameters leaves the user to rely on their experience to account for device-specific properties.
CRIS-Team WoS Importer:2021-11-12

Visceral Fat Deposition Associated with Pain in Osteoarthritis - Li, Shanshan; Desai, Nancy; Neogi, Tuhina; Schwartz, Ann; Michael, Lavalley; Wang, Na; Sun, Xianbang; Nevitt, Michael; Lewis, Beth; Guermazi, Ali; Roemer, Frank; Segal, Neil; et al. (ARTHRITIS & RHEUMATOLOGY, 2019)
CRIS-Team WoS Importer:2020-02-07

Vision, Development, and Structure of the First German Specialist Training Curriculum for Radiology - Molwitz, Isabel; Frisch, Anne; Adam, Gerhard; Afat, Saif; Ammon, Josefin; Antoch, Gerald; Baeßler, Bettina; Balks, Friederike; Barkhausen, Jörg; Bayerl, Nadine; Brendlin, Andreas; Bucher, Andreas Michael; et al. (Röfo: Fortschritte auf dem Gebiet der Röntgenstrahlen und der bildgebenden Verfahren, 2022)
CRIS-Team Scopus Importer:2022-08-12

Visualisation of tumour regression after local chemotherapy with magnetic nanoparticles - A pilot study - Lyer, Stefan; Tietze, Rainer; Jurgons, Roland; Struffert, Tobias; Engelhorn, Tobias; Schreiber, Eveline; Dörfler, Arnd; Alexiou, Christoph (Anticancer Research, 2010)
Magnetic drug targeting (MDT) is a new locoregional chemotherapy method that increases the drug dose in the tumour region, while simultaneously reducing the overall dose through the application of chemotherapeuticbound superparamagnetic nanoparticles, which are focused by an external magnetic field to the desired body compartment. An important factor in this kind of therapy is the vascularisation of the targeted tumour. In this pilot study, the visualisation of the tumour-vascularisation before and after MDT was investigated. Materials and Methods: In a rabbit VX-2 tumour model, mitoxantrone bound to Fe3O4-nanoparticles was applied through the femoral artery close to the tumour. The visualisation of vascularisation and tumour size before and after MDT was performed using a biplane angiographic system (Siemens Axiom Artis dBA) to obtain conventional angiographic series with a standard iodine contrast agent. In addition, cross-sectional images were obtained with the new technique of flat panel detector computed tomography (FD-CT) called DYNA-CT. Results: The tumours and the supplying vessels were clearly displayed by FD-CT before and after MDT. The tumours of the study group showed considerable size reductions and the angiography showed a drastic reduction of the tumour supporting vessels following MDT. Conclusion: MDT leads to significant tumour size reductions within several weeks after a single administration of chemotherapy. In this pilot study, FD-CT offered an excellent possibility to monitor the vascularisation and the size of the tumours before and after MDT.
CRIS-Team Scopus Importer:2022-06-27
Keywords: Angiography; Computed tomography; Flat-panel CT; Local chemotherapy; Magnetic drug targeting; Tumour vascularisation

Visualization of CSF Flow with Time-resolved 3D MR Velocity Mapping in Aqueductal Stenosis Before and After Endoscopic Third Ventriculostomy : A Feasibility Study - Brandner, Sebastian; Buchfelder, Michael; Eyüpoglu, Ilker Yasin; Lücking, Hannes; Dörfler, Arnd; Stadlbauer, Andreas (Clinical Neuroradiology, 2018)
PURPOSE: The aim of this study was to evaluate timed-resolved three-dimensional (3D) magnetic resonance (MR) velocity mapping as a method for investigation of cerebrospinal fluid (CSF) flow changes in patients with aqueductal stenosis (AS) treated by endoscopic third ventriculostomy (ETV). METHODS: The MR velocity mapping was performed in 12 AS patients before and after ETV and in 10 healthy volunteers by using a 3-Tesla MR system. Time-resolved 3D MR velocity mapping data were acquired with a standard 3D phase contrast (PC) sequence with cardiac triggering. Values of mean (vmean) and maximum (vpeak) velocity were measured at several ventricular structures using dedicated software. RESULTS: Of the patients 11 showed a satisfactory clinical improvement after ETV, whereas one patient needed subsequent shunt implantation. All AS patients showed significant hypomotile CSF flow dynamics in the third ventricle when compared to healthy subjects before surgery (p < 0.05). In contrast, CSF flow velocity was increased within the Foramen of Monro in AS patients. After ETV, all AS patients showed a decrease of CSF flow dynamics within the third ventricle. Mean and peak CSF flow velocities through the ventriculostomy were 1.72 ± 0.59 cm/s (vmean) and 3.53 ± 0.79 cm/s (vpeak), respectively after ETV. The patient who needed shunt implantation after ETV had the lowest flow velocities through the ventriculostomy. CONCLUSION: This study demonstrates that timed-resolved 3D MR velocity mapping is a useful imaging investigation for diagnostics and follow-up in patients with AS. This new technique provides an insight into the physiological CSF flow changes related with AS and its treatment.
EVALuna2:212790

Visualization of large vessel occlusion, clot extent, and collateral supply using volume perfusion flat detector computed tomography in acute stroke patients - Gölitz, Philipp; Lang, Stefan; Lücking, Hannes; Kalmuenzer, Bernd; Struffert, Tobias; Dörfler, Arnd; Hölter, Philip (Acta Radiologica, 2019)
Background: Flat detector computed tomography angiography (FDCTA) can be reconstructed from volume perfusion flat detector computed tomography (VP-FDCT). Thus, CTA equivalent stroke imaging might be feasible within the angio suite. Purpose: To evaluate the diagnostic accuracy of FDCTA in detecting large vessel occlusion (LVO) and collateral supply in acute stroke patients. Material and Methods: Sixteen patients with LVO of the anterior circulation were analyzed retrospectively. Each patient underwent a multimodal CT stroke protocol, subsequent VP-FDCT, and digital subtraction angiography (DSA) for endovascular stroke therapy. Angiographic images reconstructed secondarily from VP-FDCT were evaluated with regard to visualization of LVO, Collateral Score (CS), Clot Burden Score (CBS), and image quality. Results: Image quality of FDCTA was sufficient for diagnosis with a strong correlation between CTA and FDCTA (median score: CTA = 4 ± 0.447; FDCTA = 4 ± 0.5). Detection of LVO could be achieved with high sensitivity and specificity for FDCTA and CTA (97.9%, 95% confidence interval [CI] = 96.0–99.9; 92.6%, 95% CI = 84.3–100.0 vs. 96.8%, 95% CI = 93.2–100.0; 86.3%, 95% CI = 88.2–95.2). CBS and CS assessment showed no significant difference between FDCTA and CTA for both readers (reader1 CBS : P = 0.751, reader1 CS : P = 0.718; reader2 CBS : P = 0.164; reader2 CS : P = 0.582) and an excellent interrater agreement (CTA CBS ICC = 0.984, FDCTA CBS ICC = 0.951; CTA CS ICC = 0.754, FDCTA CS ICC = 0.789). Conclusion: FDCTA, reconstructed from VP-FDCT data, allows reliable detection of ICA or MCA M1 segment occlusion comparable to CTA and may provide information concerning the clot extent with sufficient image quality.
CRIS-Team Scopus Importer:2019-10-11
Keywords: Central nervous system; flat detector computed tomography; interventional; stroke

Visualization of the epimysium and fascia thoracolumbalis at the lumbar spine using MRI - Adamietz, Boris; Schoenberg, Stefan O.; Reiser, Maximilian; Uder, Michael; Frank, Andreas; Strecker, Ralph; Weiss, Christel; Heiß, Rafael (Radiologe, 2021)
Background The fascia thoracolumbalis (FTL) is an important component for stabilization and motion control of the lumbar spine. It coordinates the traction forces of the autochthonous muscles of the back (AM) and connects them to the muscles of the abdominal wall, shoulder, and buttocks. Objectives The aim of our study was to describe the assessment of the normal FTL and epimysium of the AM in MRI and to identify patterns associated with pathological changes in the lumbar spine. Material and methods A total of 33 patients were retrospectively evaluated: 15 patients had no pathology at the lumbar spine; six patients had previous hemilaminectomy, three had spondylodesis, two had ventrolisthesis, and seven had scoliosis. The thickness of the FTL and EM was measured, and the adhesion of both structures was assessed. Results The fascial thickness at the levels of the lumbar vertebral bodies LVB 3 was 1.8, of LVB 4 it was 2.0, of LVB 5 it was 2.1, and at the sacral vertebra SVB 1 it was 1.8 mm. Fascial adhesions together with thickening of the EM occurred at the level of LVB 4 in 36% of the cases independently of the underlying disorder. Only thickening of the EM was seen in 48% of cases at the level of SVB 1. By contrast, adhesion of the FTL without epimysial changes occurred in 36% of cases at the level of LVB 3. Conclusion Thickening and adhesions at the EM and FTL occurred both postoperatively and in the case of scoliosis. Furthermore, lipomatous and muscular herniation could be detected in the FTL postoperatively. Epimysial and fascial alterations may be imaging manifestations of chronic myofascial back pain and should be included in radiological assessments.
CRIS-Team WoS Importer:2021-05-28

Volume Quantification of the Thyroid Gland Using 3-D Ultrasound Imaging - Kollorz, Eva Nicole Karin; Hahn, Dieter; Grunewald, Markus; Goecke, Tamme W.; Hornegger, Joachim; Kuwert, Torsten (Nuklearmedizin Kongressausgabe 02/07, 2007)

Volumetric Regression in Brain Metastases After Stereotactic Radiotherapy: Time Course, Predictors, and Significance - Oft, Dominik; Schmidt, Manuel; Weissmann, Thomas; Roesch, Johannes; Mengling, Veit; Masitho, Siti; Bert, Christoph; Lettmaier, Sebastian; Frey, Benjamin; Distel, Luitpold; Fietkau, Rainer; Putz, Florian (Frontiers in Oncology, 2021)
Background: There is insufficient understanding of the natural course of volumetric regression in brain metastases after stereotactic radiotherapy (SRT) and optimal volumetric criteria for the assessment of response and progression in radiotherapy clinical trials for brain metastases are currently unknown. Methods: Volumetric analysis via whole-tumor segmentation in contrast-enhanced 1 mm³-isotropic T1-Mprage sequences before SRT and during follow-up. A total of 3,145 MRI studies of 419 brain metastases from 189 patients were segmented. Progression was defined using a volumetric extension of the RANO-BM criteria. A subset of 205 metastases without progression/radionecrosis during their entire follow-up of at least 3 months was used to study the natural course of volumetric regression after SRT. Predictors for volumetric regression were investigated. A second subset of 179 metastases was used to investigate the prognostic significance of volumetric response at 3 months (defined as ≥20% and ≥65% volume reduction, respectively) for subsequent local control. Results: Median relative metastasis volume post-SRT was 66.9% at 6 weeks, 38.6% at 3 months, 17.7% at 6 months, 2.7% at 12 months and 0.0% at 24 months. Radioresistant histology and FSRT vs. SRS were associated with reduced tumor regression for all time points. In multivariate linear regression, radiosensitive histology (p=0.006) was the only significant predictor for metastasis regression at 3 months. Volumetric regression ≥20% at 3 months post-SRT was the only significant prognostic factor for subsequent control in multivariate analysis (HR 0.63, p=0.023), whereas regression ≥65% was no significant predictor. Conclusions: Volumetric regression post-SRT does not occur at a constant rate but is most pronounced in the first 6 weeks to 3 months. Despite decreasing over time, volumetric regression continues beyond 6 months post-radiotherapy and may lead to complete resolution of controlled lesions by 24 months. Radioresistant histology is associated with slower regression. We found that a cutoff of ≥20% regression for the volumetric definition of response at 3 months post-SRT was predictive for subsequent control whereas the currently proposed definition of ≥65% was not. These results have implications for standardized volumetric criteria in future radiotherapy trials for brain metastases.
CRIS-Team Scopus Importer:2021-02-05
Keywords: brain metastases; longitudinal analysis; MRI; stereotactic radiosurgery; stereotactic radiotherapy; volumetric analysis; volumetric regression

Volumetry and Surgical Grading Systems for Vestibular Schwannoma Size Assessment and their Relationship to Postoperative Facial Nerve Function - Strauß, Catharina; Rampp, Stefan; Scheller, Christian; Prell, Julian; Strauss, Christian; Dörfler, Arnd; Engelhorn, Tobias (Journal of Neurological Surgery Part A: Central European Neurosurgery, 2021)
Background and Study Aims Treatment modalities in vestibular schwannoma (VS) are difficult to compare since different techniques for size measurements are used. The purpose of this study was to evaluate the relation between different tumor size grading systems regarding their compatibility as well as the relationship to facial nerve outcome facilitating comparisons of different studies.
CRIS-Team WoS Importer:2021-06-18

Voxel-wise lesion mapping of restless legs syndrome in multiple sclerosis - Fröhlich, Kilian; Knott, Michael; Hock, Stefan; Dörfler, Arnd; Seifert, Frank; Winder, Klemens (Neurological Sciences, 2022)
Objective Restless legs syndrome (RLS) is known to be associated with multiple sclerosis (MS) and may be caused by MS lesions in specific cerebral brain regions. Applying a voxel-wise lesion analysis, we tried to identify the contribution of cerebral MS lesions to RLS. Methods In this retrospective study, we established a cohort of people with MS with documented RLS and controls of people with MS without RLS matched disease severity. Diagnosis of MS and RLS was based on the current guidelines. The MS lesions were analyzed on T2-weighted magnetic resonance imaging scans (1.5 or 3 T). After manual delineation, lesion maps were converted into stereotaxic space. We generated a lesion overlap and performed a Liebermeister test with 4000 permutations to compare the absence or presence of RLS voxel-wise between patients with and without lesions in a given voxel. Results Forty of the patients with RLS and MS fulfilled the inclusion criteria. The voxel-wise analysis yielded associations between RLS and MS in the subcortex of the left gyrus precentralis. Conclusion Our voxel-wise analysis shows associations in the subcortex of the left gyrus precentralis. Thus, our data suggests that a dysfunction of the efferent motor system due to cerebral lesions may contribute to the pathophysiology of RLS in MS.
CRIS-Team WoS Importer:2022-05-20

Voxel-wise lesion mapping of self-reported urinary incontinence in multiple sclerosis - Fröhlich, Katharina; Wang, Ruihao; Bobinger, Tobias; Schmidt, Manuel; Dörfler, Arnd; Nickel, Franziska; Hilz, Max-Josef; Lee, De-Hyung; Linker, Ralf A.; Seifert, Frank; Winder, Klemens (Neurourology and Urodynamics, 2019)
Aims Besides spinal lesions, urinary incontinence may be attributed to particular cerebral lesion sites in multiple sclerosis (MS) patients. We intended to determine the contribution of suprapontine lesions to urinary incontinence in MS using a voxel-wise lesion analysis. Methods In this retrospective study, we sought MS patients with documented urinary incontinence in a local database. We established a control group of MS-patients without documented urinary incontinence matched for gender, age, and disease severity. Patients with urinary incontinence due to local diseases of the urinary tract were excluded. The MS lesions were analyzed on T2-weighted magnetic resonance imaging scans (1.5 or 3T). After manual delineation and transformation into stereotaxic space, we determined the lesion overlap and compared the presence or absence of urinary incontinence voxel-wise between patients with and without lesions in a given voxel performing the Liebermeister test with 4000 permutations. Results A total of 56 patients with urinary incontinence and MS fulfilled the criteria and were included. The analysis yielded associations between urinary incontinence and MS in the frontal white matter, temporo-occipital, and parahippocampal regions. Conclusions Our voxel-wise analysis indicated associations between self-reported urinary incontinence and lesions in the left frontal white matter and right parahippocampal region. Thus, our data suggest that dysfunction of supraspinal bladder control due to cerebral lesions may contribute to the pathophysiology of urinary incontinence in MS.
CRIS-Team WoS Importer:2019-11-12

Weight-bearing CT for knee osteoarthritis assessment: A story unfolds - Roemer, Frank (Radiology, 2021)
CRIS-Team Scopus Importer:2021-06-11

What comes first? Multitissue involvement leading to radiographic osteoarthritis: magnetic resonance imaging-based trajectory analysis over four years in the osteoarthritis initiative - Roemer, Frank; Kwoh, C. Kent; Hannon, Michael J.; Hunter, David J.; Eckstein, Felix; Fujii, Tomoko; Boudreau, Robert M.; Guermazi, Ali (Arthritis and Rheumatology, 2015)
To assess whether the presence of structural osteoarthritis (OA) features over as many as 4 years prior to incident radiographic OA increases the risk of radiographic OA in a nested, case-control design.We studied 355 knees from the Osteoarthritis Initiative cohort that developed radiographic OA before the 48-month visit. They were matched one-to-one by sex, age, and contralateral knee radiographic status with a control knee. Magnetic resonance images (MRIs) were read for bone marrow lesions (BMLs), cartilage damage, meniscal damage (including tears and extrusion), Hoffa synovitis, and effusion synovitis. Conditional logistic regression was applied to assess the risk of radiographic OA with regard to the presence of BMLs (score >=2), cartilage lesions (score >=1.1), meniscal damage (any) and extrusion of >=3 mm ± (score >=2), and Hoffa and effusion synovitis (any). Time points were defined as incident radiographic OA visit (P0), 1 year prior to the detection of radiographic OA (P -1), 2 years prior to the detection of radiographic OA (P -2), etc.The presence of Hoffa synovitis (hazard ratio [HR] 1.76 [95% confidence interval (95% CI) 1.18-2.64]), effusion synovitis (HR 1.81 [95% CI 1.18-2.78]), and medial meniscal damage (HR 1.83 [95% CI 1.17-2.89]) at P -2 predicted radiographic OA incidence. At P -1, all features but meniscal extrusion predicted radiographic OA, with highest odds for medial BMLs (HR 6.50 [95% CI 2.27-18.62]) and effusion synovitis (HR 2.50 [95% CI 1.76-3.54]). The findings at P -3 and P -4 did not reach statistical significance.Our findings indicate that the presence of specific structural features of MRI-detected joint damage 2 years prior to incident radiographic OA increases the risk of incident radiographic OA. However, 1 year prior to radiographic OA, the presence of almost any abnormal morphologic feature increases the risk of radiographic OA in the subsequent year.
EVALuna2:14541

What do we know about dynamic glucose-enhanced (DGE) MRI and how close is it to the clinics? Horizon 2020 GLINT consortium report - Kim, Mina; Eleftheriou, Afroditi; Ravotto, Luca; Weber, Bruno; Rivlin, Michal; Navon, Gil; Capozza, Martina; Anemone, Annasofia; Longo, Dario Livio; Aime, Silvio; Zaiß, Moritz; Herz, Kai; et al. (Magnetic Resonance Materials in Physics Biology and Medicine, 2022)
Cancer is one of the most devastating diseases that the world is currently facing, accounting for 10 million deaths in 2020 (WHO). In the last two decades, advanced medical imaging has played an ever more important role in the early detection of the disease, as it increases the chances of survival and the potential for full recovery. To date, dynamic glucose-enhanced (DGE) MRI using glucose-based chemical exchange saturation transfer (glucoCEST) has demonstrated the sensitivity to detect both d-glucose and glucose analogs, such as 3-oxy-methyl-d-glucose (3OMG) uptake in tumors. As one of the recent international efforts aiming at pushing the boundaries of translation of the DGE MRI technique into clinical practice, a multidisciplinary team of eight partners came together to form the "glucoCEST Imaging of Neoplastic Tumors (GLINT)" consortium, funded by the Horizon 2020 European Commission. This paper summarizes the progress made to date both by these groups and others in increasing our knowledge of the underlying mechanisms related to this technique as well as translating it into clinical practice.
CRIS-Team WoS Importer:2022-01-28

What effect is really being measured? An alternative explanation of paradoxical phenomena in studies of osteoarthritis progression - Zhang, Yuqing; Neogi, Tuhina; Hunter, David; Roemer, Frank; Niu, Jingbo (Arthritis & Rheumatism-Arthritis Care & Research, 2014)
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What is New in Osteoarthritis Imaging? - Chalian, Majid; Pooyan, Atefe; Alipour, Ehsan; Roemer, Frank; Guermazi, Ali (Radiologic Clinics of North America, 2024)
CRIS-Team Scopus Importer:2024-03-29
Keywords: Imaging; Magnetic resonance imaging; Osteoarthritis; Radiology

What is the hemodynamic effect of the Woven EndoBridge? An in vivo quantification using time-density curve analysis - Gölitz, Philipp; Lücking, Hannes; Hölter, Philip; Knossalla, Frauke; Dörfler, Arnd (Neuroradiology, 2020)
Purpose: Using the Woven EndoBridge (WEB) for aneurysm treatment has emerged as endovascular approach aiming for flow disruption in aneurysm sac. Since quantifiable data confirming the hemodynamic effect are lacking, we investigated in vivo aneurysmal flow alterations using time-density curve (TDC) analysis. Additionally, we evaluated whether flow parameters could be identified as independent factor to predict aneurysm occlusion. Methods: Forty cerebral aneurysm patients treated with WEB were enrolled. Pre- and postinterventional digital subtraction angiography series were postprocessed and TDCs generated. TDCs were quantified calculating the parameters aneurysmal inflow velocity, outflow velocity, mean flow velocity, and relative time-to-peak (rTTP) of aneurysm filling. Pre- and postinterventional values were compared and related to occlusion rate. Results: WEB implanting induced highly significant rTTP prolongation by 52% (p = 0.001) and highly significant decrease of aneurysmal inflow, outflow, and mean flow velocity (p < 0.001). While outflow velocity was reduced by 49%, inflow velocity was reduced by 33% only. No statistically significant difference between the occluded and the non-occluded group was observed. No flow parameter reached significance level concerning predicting aneurysm occlusion. Conclusion: Flow quantification confirms a significant flow-disrupting effect of WEB reducing more the outflow than the inflow velocity. In our small cohort, no flow parameter reached statistical significance to show predictive value regarding complete aneurysm occlusion. The hemodynamic effect of WEB is on comparable level to flow-diverting stents meaning that aneurysm closure can be delayed. In case of only slight inflow changes and high aneurysmal hemodynamic stress, some aneurysms might not be adequately protected in the short term.
CRIS-Team Scopus Importer:2020-03-27
Keywords: Aneurysm; Digital subtraction angiography; Hemodynamics; Image postprocessing; Intrasaccular flow diverter; Time-density curve

What is the role of 3 T MRI in sports medicine? Revisiting the marriage after the honeymoon - Roemer, Frank; Guermazi, Ali (British Journal of Sports Medicine, 2016)
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WHEN THE 'WHOLE' IS MORE THAN A 'SUM' OF ITS PARTS: QUANTIFYING TOTAL BURDEN OF KNEE OA USING SEMI-QUANTITATIVE KNEE MRI ASSESSMENT - Collins, J. E.; Hunter, D. J.; Guermazi, A.; Roemer, Frank; Katz, J. N.; Losina, E. (2018)
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Which Is Better for Characterizing Disease Activity in Axial Spondyloarthritis: Diffusion MRI or T2-weighted/STIR MRI? - Guermazi, Ali; Roemer, Frank (Radiology, 2019)
CRIS-Team WoS Importer:2019-05-09

Which risk factors determine cartilage thickness and composition change in radiographically normal knees? – Data from the Osteoarthritis Initiative - Eckstein, F.; Maschek, S.; Culvenor, A.; Sharma, L.; Roemer, Frank; Duda, G. N.; Wirth, W. (Osteoarthritis and Cartilage Open, 2023)
Objective: Therapy for osteoarthritis ideally aims at preserving structure before radiographic change occurs. This study tests: a) whether longitudinal deterioration in cartilage thickness and composition (transverse relaxation-time T2) are greater in radiographically normal knees “at risk” of incident osteoarthritis than in those without risk factors; and b) which risk factors may be associated with these deteriorations. Design: 755 knees from the Osteoarthritis Initiative were studied; all were bilaterally Kellgren Lawrence grade [KLG] 0 initially, and had magnetic resonance images available at 12- and 48-month follow-up. 678 knees were “at risk”, whereas 77 were not (i.e., non-exposed reference). Cartilage thickness and composition change was determined in 16 femorotibial subregions, with deep and superficial T2 being analyzed in a subset (n ​= ​59/52). Subregion values were used to compute location-independent change scores. Results: In KLG0 knees “at risk”, the femorotibial cartilage thinning score (−634 ​± ​516 ​μm) over 3 years exceeded the thickening score by approximately 20%, and was 27% greater (p ​< ​0.01; Cohen D −0.27) than the thinning score in “non-exposed” knees (−501 ​± ​319 ​μm). Superficial and deep cartilage T2 change, however, did not differ significantly between both groups (p ​≥ ​0.38). Age, sex, body mass index, knee trauma/surgery history, family history of joint replacement, presence of Heberden's nodes, repetitive knee bending were not significantly associated with cartilage thinning (r2<1%), with only knee pain reaching statistical significance. Conclusions: Knees “at risk” of incident knee OA displayed greater cartilage thinning scores than those “non-exposed”. Except for knee pain, the greater cartilage loss was not significantly associated with demographic or clinical risk factors.
CRIS-Team Scopus Importer:2023-07-28
Keywords: Cartilage; Cartilage loss; Cartilage thickness; Magnetic resonance imaging (MRI); Risk factors; Transverse relaxation time

White paper: clinical studies in radiology - Antoch, G.; Barkhausen, J.; Dueber, C.; Epsch, R.; Heindel, W.; Krombach, G.; Maintz, D.; Schlemmer, H. P.; Schoenberg, S.; Wigge, P.; Adam, G.; Beer, M.; et al. (Röfo-Fortschritte auf dem Gebiet der Röntgenstrahlen und der bildgebenden Verfahren, 2014)
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White Paper: Radiological Curriculum for Undergraduate Medical Education in Germany - Ertl-Wagner, Birgit; Barkhausen, J.; Mahnken, A. H.; Mentzel, H. J.; Uder, Michael; Weidemann, J.; Stumpp, P.; et al. (Röfo: Fortschritte auf dem Gebiet der Röntgenstrahlen und der bildgebenden Verfahren, 2016)
Purpose: Radiology represents a highly relevant part of undergraduate medical education from preclinical studies to subinternship training. It is therefore important to establish a content base for teaching radiology in German Medical Faculties. Materials and Methods: The German Society of Radiology (DRG) developed a model curriculum for radiological teaching at German medical universities, which is presented in this article. There is also a European model curriculum for undergraduate teaching (U-level curriculum of the European Society of Radiology). In a modular concept, the students shall learn important radiological core principles in the realms of knowledge, skills and competences as well as core scientific competences in the imaging sciences. Results: The curriculum is divided into two modules. Module 1 includes principles of radiation biology, radiation protection and imaging technology, imaging anatomy as well as the risks and side effects of radiological methods, procedures and contrast media. This module is modality-oriented. Module 2 comprises radiological diagnostic decision-making and imaging-based interventional techniques for various disease entities. This module is organ system-oriented. Conclusion: The curriculum is meant as a living document to be amended and revised at regular intervals. The curriculum can be used as a basis for individual curricular development at German Medical Faculties. It can be integrated into traditional or reformed medical teaching curricula. Key Points: • Radiology is an integral and important part of medical education. • The German Society of Radiology (DRG) developed a model curriculum for teaching radiology at German Medical Faculties to help students develop the ability to make medical decisions based on scientific knowledge and act accordingly. • This curriculum can be used for individual curricular development at medical departments. It is divided into two modules with several chapters. Citation Format: • Ertl-Wagner B, Barkhausen J, Mahnken AH et al. White Paper: Radiological Curriculum for Undergraduate Medical Education in Germany. Fortschr Röntgenstr 2016; 188: 1017 1023.
CRIS-Team Scopus Importer:2023-03-08
Keywords: competence-based learning; curriculum; medical education; radiological teaching; undergraduate teaching

Whole body low dose CT to assess overall burden of osteoarthritis: development of an atlas and reliability testing of a new scoring system - Gielis, W.; Foppen, W.; Nap, F. J.; Roemer, Frank; Weinans, H.; De Jong, P. A. (OSTEOARTHRITIS AND CARTILAGE, 2019)
CRIS-Team WoS Importer:2019-05-21

Whole body magnetic resonance angiography and computed tomography angiography in the vascular mapping of head and neck: an intraindividual comparison - Kramer, Manuel; Schwab, Siegfried; Nkenke, Emeka; Eller, Achim; Kammerer, Ferdinand; May, Matthias; Baigger, Joao F.; Uder, Michael; Lell, Michael (Head & Face Medicine, 2014)
The aim of the study was to compare the detectability of neck vessels with contrast enhanced magnetic resonance angiography (MRA) in the setting of a whole-body MRA and multislice computed tomography angiography (CTA) for preoperative vascular mapping of head and neck.In 20 patients MRA was performed prior to microvascular reconstruction of the mandible with osteomyocutaneous flaps. CTA of the neck served as the method of reference.1.5 T contrast enhanced magnetic resonance angiograms were acquired to visualize the vascular structures of the neck in the setting of a whole-body MRA examination. 64-slice spiral computed tomography was performed with a dual-phase protocol, using the arterial phase images for 3D CTA reconstruction. Maximum intensity projection was employed to visualize MRA and CTA data. To retrieve differences in the detectability of vessel branches between MRA and CTA, a McNemar test was performed.All angiograms were of diagnostic quality. There were no statistically significant differences between MRA and CTA for the detection of branches of the external carotid artery that are relevant host vessels for microsurgery (p = 0.118). CTA was superior to MRA if all the external carotid artery branches were included (p < 0.001).MRA is a reliable alternative to CTA in vascular mapping of the cervical vasculature for planning of microvascular reconstruction of the mandible. In the setting of whole-body MRA it could serve as a radiation free one-stop-shop tool for preoperative assessment of the arterial system, potentially covering both, the donor and host site in one single examination.
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Whole-body magnetic resonance imaging plus serological follow-up for early identification of progression in smouldering myeloma patients to prevent development of end-organ damage - Wennmann, Markus; Goldschmidt, Hartmut; Mosebach, Jennifer; Hielscher, Thomas; Bäuerle, Tobias; Komljenovic, Dorde; Mccarthy, Philip L.; Merz, Maximilian; Schlemmer, Heinz-Peter; Raab, Marc-Steffen; Sauer, Sandra; Delorme, Stefan; et al. (British Journal of Haematology, 2022)
The definition of multiple myeloma (MM) was updated in 2014, with the intent to enable earlier treatment and thereby avoid appearance of end-organ damage at progression from smouldering multiple myeloma (SMM) to MM. The purpose of this study was to investigate to which extent the development of end-organ damage at progression to MM was reduced under the updated guidelines. In this prospective observational cohort study (ClinicalTrials.gov Identifier: NCT01374412), between 2014 and 2020, 96 SMM patients prospectively underwent whole-body magnetic resonance imaging (wb-MRI) and serological follow-up at baseline and every 6 months thereafter. A total of 22 patients progressed into MM during follow-up, of which seven (32%) showed SLiM-criteria only but no end-organ damage. Four (57%) of the seven patients who progressed by SLiM-criteria only progressed with >1 focal lesion (FL) or a growing FL, and three (43%) due to serum free light-chain-ratio ≥100. Fifteen (68%) out of 22 patients who progressed still suffered from end-organ damage at progression. The updated disease definition reduced the proportion of SMM patients suffering from end-organ damage at progression to MM by one third. wb-MRI is an important tool for detection of SMM patients who progress to MM without end-organ damage.
CRIS-Team Scopus Importer:2022-06-03
Keywords: end-organ damage; multiple myeloma; progression; smouldering multiple myeloma; whole-body MRI

Whole-brain quantitative CEST MRI at 7T using parallel transmission methods and B1+ correction - Liebert, Andrzej; Tkotz, Katharina; Herrler, Jürgen; Linz, Peter; Mennecke, Angelika; German, Alex; Liebig, Patrick; Gumbrecht, Rene; Schmidt, Manuel; Dörfler, Arnd; Uder, Michael; Zaiß, Moritz; et al. (Magnetic Resonance in Medicine, 2021)
Purpose: To enable whole-brain quantitative CEST MRI at ultra-high magnetic field strengths (B0 ≥ 7T) within short acquisition times. Methods: Multiple interleaved mode saturation (MIMOSA) was combined with fast online-customized (FOCUS) parallel transmission (pTx) excitation pulses and (Formula presented.) correction to achieve homogenous whole-brain coverage. Examinations of 13 volunteers were performed on a 7T MRI system with 3 different types of pulse sequences: (1) saturation in circular polarized (CP) mode and CP mode readout, (2) MIMOSA and CP readout, and (3) MIMOSA and FOCUS readout. For comparison, the inverse magnetic transfer ratio metric for relayed nuclear Overhauser effect and amide proton transfer were calculated. To investigate the number of required acquisitions for a good (Formula presented.) correction, 4 volunteers were measured with 6 different B1 amplitudes. Finally, time point repeatability was investigated for 6 volunteers. Results: MIMOSA FOCUS sequence using (Formula presented.) correction, with both single and multiple points, reduced inhomogeneity of the CEST contrasts around the occipital lobe and cerebellum. Results indicate that the most stable inter-subject coefficient of variation was achieved using the MIMOSA FOCUS sequence. Time point repeatability of MIMOSA FOCUS with single-point (Formula presented.) correction showed a maximum coefficient of variation below 8% for 3 measurements in a single volunteer. Conclusion: A combination of MIMOSA FOCUS with a single-point (Formula presented.) correction can be used to achieve quantitative CEST measurements at ultra-high magnetic field strengths. Compared to previous (Formula presented.) correction methods, acquisition time can be reduced as additional scans required for (Formula presented.) correction can be omitted.
CRIS-Team Scopus Importer:2021-03-12
Keywords: 7T; chemical exchange saturation transfer; fast-online customized pulses; multiple interleaved mode saturation; parallel transmission; spiral non-selective trajectory

Whole brain snapshot CEST at 3T using 3D-EPI: Aiming for speed, volume, and homogeneity - Mueller, Sebastian; Stirnberg, Rüdiger; Akbey, Suzan; Ehses, Philipp; Scheffler, Klaus; Stöcker, Tony; Zaiß, Moritz (Magnetic Resonance in Medicine, 2020)
Purpose: CEST MRI enables imaging of distributions of low-concentrated metabolites as well as proteins and peptides and their alterations in diseases. CEST examinations often suffer from low spatial resolution, long acquisition times, and concomitant motion artifacts. This work aims to maximize both resolution and volume coverage with a 3D-EPI snapshot CEST approach at 3T, allowing for fast and robust whole-brain CEST MRI. Methods: Resolution and temporal SNR of 3D-EPI examinations with nonselective excitation were optimized at a clinical 3T MR scanner in five healthy subjects using a clinical head/neck coil. A CEST presaturation module for low power relayed nuclear Overhauser enhancement and amide proton transfer contrast was applied as an example. The suggested postprocessing included motion correction, dynamic B0 correction, denoising, and B1 correction and was compared to an established 3D-gradient echo-based sequence. Results: CEST examinations were performed at 1.8 mm nominal isotropic resolution in 4.3 s per presaturation offset. In contrast to slab-selective 3D or multislice approaches, the whole brain was covered. Repeated examinations at three different B1 values took 13 minutes for 58 presaturation offsets with temporal SNR around 75. The resulting CEST effects revealed significant gray and white matter contrast and were of similar quality across the whole brain. Coefficient of variation across three healthy subjects was below 9%. Conclusion: The suggested protocol enables whole brain coverage at 1.8 mm isotropic resolution and fast acquisition of 4.3 s per presaturation offset. For the fitted CEST amplitudes, high reproducibility was proven, increasing the opportunities of quantitative CEST investigations at 3T significantly.
CRIS-Team Scopus Importer:2020-05-19
Keywords: 3D CEST MRI; chemical exchange saturation transfer MRI 3T; chemical exchange saturation transfer MRI EPI; high resolution CEST MRI; whole-brain CEST MRI

Whole joint MRI assessment of surgical cartilage repair of the knee: cartilage repair osteoarthritis knee score (CROAKS) - Roemer, Frank; Guermazi, A.; Trattnig, S.; Apprich, S.; Marlovits, S.; Niu, J.; Hunter, D. J.; Welsch, Götz (Osteoarthritis and Cartilage, 2014)
To develop a magnetic resonance imaging (MRI) scoring system for follow-up of knee cartilage repair procedures integrating assessment of the repair site and the whole joint called Cartilage Repair OsteoArthritis Knee Score (CROAKS), and to assess its reliability.MRI examinations of 20 patients that had undergone matrix-associated autologous chondrocyte transplantation (MACT) of the knee 12 months before were semi-quantitatively assessed for the repair site using features of the magnetic resonance observation of cartilage repair tissue (MOCART) system and for the whole joint based on experiences with the MRI Osteoarthritis Knee Score (MOAKS) instrument. Intra- and inter-observer reliability was calculated using weighted (w) kappa statistics for plates (medial/lateral tibia, medial/lateral femur, trochlea, patella), compartments (medial tibio-femoral, lateral tibio-femoral, patello-femoral) and the whole joint. For certain features with low prevalence the overall percent agreement was calculated in addition.For cartilage, reliability on a plate level ranged between 0.48 (lateral femur) and 1.00 (medial femur). BML assessment showed comparable results ranging on a plate level between 0.46 and 1.00 with overall percent agreement between 83.3% and 100%. Meniscal morphology assessment ranged between 0.62 and 0.94. For repair site assessment reliability ranged from 0.41 (signal intensity inter-observer) to 1.00 (several features). Overall percent agreement was above 80% for 17 of 22 features assessed (intra- and inter-observer results combined).Combined scoring of the repair site and whole joint assessment for common osteoarthritis features using CROAKS, which is based on experience with two established semi-quantitative scoring tools, is feasible and may be performed with good to excellent reliability.
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Why Does It Shine?-A Prognostic Analysis about Predisposing Factors for Blood-Brain Barrier Damage after Revascularisation of Cerebral Large-Vessel Occlusion. - Knott, Michael; Hock, Stefan; Soder, Liam; Mühlen, Iris; Kremer, Svenja; Sprügel, Maximilian; Sembill, Jochen; Kuramatsu, Joji; Schwab, Stefan; Engelhorn, Tobias; Dörfler, Arnd (Journal of Cardiovascular Development and Disease, 2023)
BACKGROUND: Hyperdense lesions in CT after EVT of LVO are common. These lesions are predictors for haemorrhages and an equivalent of the final infarct. The aim of this study based on FDCT was the evaluation of predisposing factors for these lesions. METHODS: Using a local database, 474 patients with mTICI ≥ 2B after EVT were recruited retrospectively. A postinterventional FDCT after recanalisation was analysed regarding such hyperdense lesions. This was correlated with a variety of items (demographics, past medical history, stroke assessment/treatment and short-/long-term follow-up). RESULTS: Significant differences were present in NHISS at admission, regarding time window, ASPECTS in initial NECT, location of the LVO, CT-perfusion (penumbra, mismatch ratio), haemostatic parameters (INR, aPTT), duration of EVT, number of EVT attempts, TICI, affected brain region, volume of demarcation and FDCT-ASPECTS. The ICH-rate, the volume of demarcation in follow-up NECT and the mRS at 90 days differed in association with these hyperdensities. INR, the location of demarcation, the volume of demarcation and the FDCT-ASPECTS could be demonstrated as independent factors for the development of such lesions. CONCLUSION: Our results support the prognostic value of hyperdense lesions after EVT. We identified the volume of the lesion, the affection of grey matter and the plasmatic coagulation system as independent factors for the development of such lesions.
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Woman with sudden-onset speech difficulties. - To, Vi Tuong Daniel; Marterstock, Dominique; Madžar, Dominik (Journal of the American College of Emergency Physicians Open, 2023)
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Work and Training Conditions of German Residents in Radiology - Results from a Nationwide Survey Conducted by the Young Radiology Forum in the German Roentgen Society - Oechtering, Thekla H.; Panagiotopoulos, Nikolaos; Völker, Martin; Lohwasser, Stefan; Ellmann, Stephan; Molwitz, Isabel; Storz, Corinna; Winther, Hinrich; Eisenblaetter, Michel; Antoch, Gerald; Schönberg, Stefan O.; Barkhausen, Jörg; et al. (Röfo-Fortschritte auf dem Gebiet der Röntgenstrahlen und der bildgebenden Verfahren, 2020)
Purpose Good training is the basis for high job satisfaction and high-quality patient care in radiology. The aim of this survey was to record the current state of working conditions for residents in radiology training in Germany and to focus on the aspects of training and psychosocial workload. The description of the actual state should help to identify possible problem areas and to develop improvement approaches. Materials and Methods At the beginning of 2018, we sent an electronic questionnaire to the German Roentgen Society (DRG), the German Association of Chairmen in Academic Radiology (KLR), the Chief Physician Forum of the DRG (CAFRAD) and the Forum of Registered Radiologists (FUNRAD) with the request to forward it to radiology residents. With 63 questions, the questionnaire covered seven essential areas of medical working and training conditions. In order to ensure interdisciplinary comparability, most questions were identical to previous surveys among residents of other disciplines. Results 643 residents started the survey. 501 (78 %) questionnaires were fully processed and included in the final analysis. 65 % of respondents were satisfied with their current job situation. At the same time, shortcomings, especially with regard to the reconciliation of family and work as well as scientific and clinical work, became clear. Only 36 % of participants with children were satisfied with the compatibility of family and work at their workplace. Only 31 % of the researchers were satisfied with their research conditions. In addition, residents experienced a high psychosocial workload. Conclusion Job satisfaction is high among radiology residents in direct comparison to other disciplines. However, based on this survey, adjustments to working conditions and training in radiology seem necessary to maintain the health of the physicians concerned, to encourage motivation for scientific work and to enhance development opportunities, especially for women, through a better compatibility of work and family life. The present survey identifies strategies and leadership tools that can help to achieve this. Key Points: Residents in radiology training.. have a relatively high job satisfaction. experience a high psychosocial workload. evaluate the compatibility of family and work as in need of improvement. are interested in research, but evaluate research conditions as insufficient Citation Format Oechtering TH, Panagiotopoulos N, Völker M et al. Work and Training Conditions of German Residents in Radiology - Results from a Nationwide Survey Conducted by the Young Radiology Forum in the German Roentgen Society. Fortschr Röntgenstr 2020; 192: 458 - 469
CRIS-Team Scopus Importer:2020-05-22
Keywords: continuing education; ER-ratio; psychosocial workload; radiology; resident; working conditions

Worsening of Articular Tissue Damage as Defined by Semi-Quantitative MRI Is Associated With Concurrent Quantitative Cartilage Loss Over 24 Months - Roemer, Frank; Maschek, Susanne; Wisser, Anna; Guermazi, Ali; Hunter, David; Eckstein, Felix; Wirth, Wolfgang (Cartilage, 2023)
Objective: To assess the association of worsening of magnetic resonance imaging (MRI) semi-quantitative (SQ) tissue features with concurrent change in quantitative (Q) cartilage thickness measurements over 24 months within the Foundation for the National Institutes of Health (FNIH) Biomarker Consortium study. Methods: In all, 599 participants were included. SQ assessment included cartilage damage, meniscal extrusion and damage, osteophytes, bone marrow lesions (BMLs), and effusion- and Hoffa-synovitis. Change in medial compartment Q cartilage thickness was stratified by concurrent ipsicompartmental SQ changes. Between-group comparisons were performed using analysis of covariance (ANCOVA) with adjustment for age, sex, and body mass index (BMI). Results were presented as adjusted mean difference. Results: Knees with any increase in SQ cartilage scores in the medial compartment (n = 268) showed more Q cartilage loss compared to knees that remained stable (mean adjusted difference [MAD] = -0.16 mm, 95% confidence interval [CI]: [-0.19, -0.13] mm). Knees with any increase in meniscal extrusion in the medial compartment (n = 98) showed more Q cartilage loss than knees without (MAD = -0.18 mm, 95% CI: [-0.22, -0.14] mm. Comparable findings were seen for meniscal damage worsening. Regarding BMLs, an increase by one subregion resulted in a MAD of Q cartilage loss of -0.10 mm, 95% CI: [-0.14, -0.06] mm, while this effect almost tripled for change in two or more subregions. Increase in either effusion- and/or Hoffa-synovitis by one grade resulted in a MAD of -0.07 mm, 95% CI: [-0.10, -0.03] mm. Conclusion: Worsening of SQ cartilage damage, meniscal extrusion and damage, number of subregions affected by BML, maximum size of BMLs and worsening of effusion- and/or Hoffa synovitis is associated with increased Q cartilage loss.
CRIS-Team Scopus Importer:2023-01-20
Keywords: cartilage; knee; MRI; osteoarthritis

Wrist injuries detected on magnetic resonance imaging in athletes participating in the Rio de Janeiro 2016 Summer Olympic Games - Alizai, Hamza; Engebretsen, Lars; Jarraya, Mohamed; Roemer, Frank; Guermazi, Ali (Quantitative Imaging in Medicine and Surgery, 2021)
Background: Traumatic and chronic overuse injuries of the wrist are common in athletes. The purpose of this study was to describe the frequency, anatomic distribution, and severity of MRI-detected wrist joint injuries amongst athletes who competed in the Rio de Janeiro 2016 Summer Olympics. Methods: All sports injuries reported by the National Olympic Committee medical teams and the Organizing Committee medical staff during the 2016 Summer Olympics were analyzed. MRI was performed at the International Olympic Committee's polyclinic within the Olympic Village, using 3T and 1.5T scanners. The MRIs were interpreted by musculoskeletal radiologists with expertise in sports injuries. The distribution of wrist injuries by anatomic location and sports discipline and the severity of injuries were recorded. Results: A total of 1,101 injuries were reported in the 11,274 athletes. Twenty-five athletes (72% male, median-age =27 years) had an MRI for wrist injuries. Fifty-six percent (N=14) of these athletes had triangular fibrocartilage pathology, 64% of which were chronic, while 36% were acute. There were scapholunate ligament injuries in 40% of the athletes. The extensor carpi ulnaris tendon was most commonly injured tendon. Fractures were seen in 32% of the athletes (N=8) and most commonly involved the scaphoid. Athletes participating in weightlifting (N=4, 16%), tennis (N=3, 12%) and gymnastics (N=3, 12%) athletes were most commonly affected. Conclusions: MRI-detected wrist injuries during the 2016 Summer Olympics most commonly affected the scapholunate ligament, extensor carpi ulnaris tendon and triangular fibrocartilage articular disc. The highest occurrence of wrist injuries was in weightlifting, tennis and gymnastics.
CRIS-Team Scopus Importer:2021-06-11
Keywords: Magnetic Resonance Imaging; Wrist injuries; Olympic Games

X-Ray Induced Formation of γ-H2AX Foci after Full-Field Digital Mammography and Digital Breast-Tomosynthesis - Schwab, Siegfried; Brand, Michael; Schlude, Ina-Kristin; Wüst, Wolfgang; Meier-Meitinger, Martina; Distel, Luitpold; Schulz-Wendtland, Rüdiger; Uder, Michael; Uder, Michael; Kuefner, Michael A. (PLoS ONE, 2013)
Purpose:To determine in-vivo formation of x-ray induced γ-H2AX foci in systemic blood lymphocytes of patients undergoing full-field digital mammography (FFDM) and to estimate foci after FFDM and digital breast-tomosynthesis (DBT) using a biological phantom model.Materials and Methods:The study complies with the Declaration of Helsinki and was performed following approval by the ethic committee of the University of Erlangen-Nuremberg. Written informed consent was obtained from every patient. For in-vivo tests, systemic blood lymphocytes were obtained from 20 patients before and after FFDM. In order to compare in-vivo post-exposure with pre-exposure foci levels, the Wilcoxon matched pairs test was used. For in-vitro experiments, isolated blood lymphocytes from healthy volunteers were irradiated at skin and glandular level of a porcine breast using FFDM and DBT. Cells were stained against the phosphorylated histone variant γ-H2AX, and foci representing distinct DNA damages were quantified.Results:Median in-vivo foci level/cell was 0.086 (range 0.067-0.116) before and 0.094 (0.076-0.126) after FFDM (p = 0.0004). In the in-vitro model, the median x-ray induced foci level/cell after FFDM was 0.120 (range 0.086-0.140) at skin level and 0.035 (range 0.030-0.050) at glandular level. After DBT, the median x-ray induced foci level/cell was 0.061 (range 0.040-0.081) at skin level and 0.015 (range 0.006-0.020) at glandular level.Conclusion:In patients, mammography induces a slight but significant increase of γ-H2AX foci in systemic blood lymphocytes. The introduced biological phantom model is suitable for the estimation of x-ray induced DNA damages in breast tissue in different breast imaging techniques. © 2013 Schwab et al.
CRIS-Team Scopus Importer:2023-03-08

Zukunft mammographie-basierter Bildgebung [Future of mammography-based imaging] - Schulz-Wendtland, Rüdiger; Wittenberg, Thomas; Michel, Thilo; Hartmann, Arndt; Beckmann, Matthias; Rauh, Claudia; Judt, Sebastian; Brehm, Barbara; Meier-Meitinger, Martina; Anton, Gisela; Uder, Michael; Fasching, Peter (Radiologe, 2014)
Mammography is the central diagnostic method for clinical diagnostics of breast cancer and the breast cancer screening program. In the clinical routine complementary methods, such as ultrasound, tomosynthesis and optional magnetic resonance imaging (MRI) are already combined for the diagnostic procedure. Future developments will utilize investigative procedures either as a hybrid (combination of several different imaging modalities in one instrument) or as a fusion method (the technical fusion of two or more of these methods) to implement fusion imaging into diagnostic algorithms. For screening there are reasonable hypotheses to aim for studies that individualize the diagnostic process within the screening procedure. Individual breast cancer risk prediction and individualized knowledge about sensitivity and specificity for certain diagnostic methods could be tested. The clinical implementation of these algorithms is not yet in sight. (orig.) [German] Die Mammographie ist die zentrale diagnostische Methode der klinischen symptombezogenen Abklaerung von Brusterkrankungen und des Brustkrebsscreenings. In der klinischen Diagnostik wird sie heute schon oft durch zusaetzliche Untersuchungsmethoden wie dem Ultraschall, der Tomosynthese und ggf. auch der MRT-Bildgebung unterstuetzt. Zukuenftige Entwicklungen gehen in die Richtung, dass diese Kombination aus 2 oder mehr Untersuchungsverfahren entweder in Hybrid- (Aufnahme mehrerer unterschiedlicher Bildmodalitaeten in einem einzigen Geraet) oder in Fusionsmethoden (Zusammenfuehrung und Registrierung von Bilddaten aus verschiedenen Modalitaeten) technisch professionalisiert werden. Des Weiteren koennten an subgruppenbezogene Erkrankungsrisiken und individuelle Sensitivitaeten und Spezifitaeten angepasste Diagnostikkombinationen fuer eine Screeningdiagnostik Gegenstand kuenftiger Studien sein. Wir stellen die aktuellen Entwicklungen auf diesen Gebieten und deren momentane Relevanz fuer die klinische Praxis und Entwicklungspotenzial fuer die Zukunft dar. (orig
UnivIS-Import:2015-04-14:Pub.2014.tech.IMMD.IMMD9.zukunf
Keywords: MAMMOgraphy

Zusammengefasste Empfehlungen für ein körperliches Training zur Frakturprophylaxe postmenopausaler Frauen und Männer 45 Jahre und älter - von Stengel, Simon; Schöne, Daniel; Kohl, Matthias; Becker, Clemens; Gosch, Markus; Jakob, Franz; Kerschan-Schindl, Katharina; Kladny, Bernd; Lange, Uwe; Peters, Stefan; Sieber, Cornel; Thomasius, Friederike; et al. (Osteologie, 2023)
The design and implementation of promising training protocols for fracture prevention is a multi-step approach that has to consider a wide range of diverging aspects. Apart from the effectiveness as such, a large number of individual, logistical and financial aspects have to be taken into account to generate ideally persistantly applicable exercise training programs. Applying a sport scientific approach, the definition of dedicated training aims, based on the individual fracture risk profile, is the first step of the training process. The appropriate selection of training content and types along with training tools and methods that best possibly address the defined training aim(s) should also consider the (fracture) risk profile, health status and predispositions of the individual. Since training programs should be maintained as long as possible, ideally for life, particular attention should be paid to training principles (e. g. progressive overload, periodization), something often overlooked in scientific studies of limited duration. Summing up the applicability of exercise programms for fracture prevention, in view of the large variaty of training options and technologies, exercise is a feasible and promizing therapy for most if not all cohorts at risk for fractures - individually adjustable relating to functional status, health issues and potential contraindications. With the exception of structures for fall prevention programs as an individual home-based approach, health care systems already provide closely supervised, qualified and co-financed training programs that could be increasingly used as vehicles for fracture prevention. Unfortunately, the broad applicability of training programs on fracture prevention for almost all risk and propensity groups is often stymied by the frequently insufficient level of information of stakeholders and decision-makers regarding effectiveness, feasibility and applicability of exercise.
CRIS-Team Scopus Importer:2023-09-22
Keywords: contraindications; exercise training; fracture prevention; recommendations; setting

КАК ИСПОЛЬЗОВАТЬ ШКАЛУ КАЙЗЕРА ДЛЯ ПРИНЯТИЯ ДИАГНОСТИЧЕСКИХ РЕШЕНИЙ ПРИ МУЛЬТИПАРАМЕТРИЧЕСКОЙ МРТ МОЛОЧНОЙ ЖЕЛЕЗЫ - Dietzel, Matthias; Mazo, M. L.; Rozhkova, N. V.; Kharuzhyk, S. A.; Kuplevatskaya, D. I.; Busko, E. A.; Hodikan, G. K.; Baltzer, P. A.T. (Russian Electronic Journal of Radiology, 2020)
Purpose. Development of a universal system for evaluating MRI images of the breast. Material and methods. Due to its superior sensitivity, breast MRI (bMRI) has been established as an important additional diagnostic tool in the breast clinic and is used for screening in patients with an elevated risk for breast cancer. Results. Breast MRI, however, is a complex tool, providing multiple images containing several contrasts. Thus, reading bMRI requires a structured approach. A lack of structure will increase the rate of false-positive findings and sacrifice most of the advantages of bMRI as additional work-up will be required. While the BI-RADS (Breast Imaging Reporting And Data System) lexicon is a major step toward standardised and structured reporting, it does not provide a clinical decision rule with which to guide diagnostic decisions. Such a clinical decision rule, however, is provided by the Kaiser score, which combines five independent diagnostic BI-RADS lexicon criteria (margins, SI-time curve type, internal enhancement and presence of oedema) in an intuitive flowchart. Conclusion. The resulting score provides probabilities of malignancy that can be used for evidence-based decision-making in the breast clinic. Notably, considerable benefits have been demonstrated for radiologists with initial and intermediate experience in bMRI. This pictorial essay is a practical guide to the application of the Kaiser score in the interpretation of breast MRI examinations. Teaching Points. 1)bMRI requires standardisation of patient-management, protocols, and reading set-up. 2) Reading bMRI includes the assessment of breast parenchyma, associated findings, and lesions. 3) Diagnostic decisions should be made according to evidence-based clinical decision rules. 4) The evidence-based Kaiser score is applicable independent of bMRI protocol and scanner. 5) The Kaiser score provides high diagnostic accuracy with low inter-observer variability.
CRIS-Team Scopus Importer:2020-12-18
Keywords: Breast cancer; BreastMRI; Patientmanagement; сlinical decision-making

Artificial intelligence-based algorithms Decision-making support for computed tomography of the chest - Manava, Panagiota; Galster, Marco; Heinen, Henrik; Stebner, Alexander; Lell, Michael (Radiologe, 2020)
Artificial intelligence (AI) algorithms are increasingly used in radiology. The main areas of application are, for example, the detection of lung lesions and the diagnosis of chronic obstructive and interstitial lung diseases. The aim of our study was to train and evaluate a package of algorithms that analyze data from computed tomographic (CT) images of the chest and provide quantitative measurements to the radiologist. The following algorithms were trained: lung lesion detection and measurement, lung lobe segmentation, vessel segmentation and measurement, coronary calcium scoring, measurement and density analysis of vertebral bodies. AI-supported algorithms will become part of daily routine of the radiologist in the future. Tasks that do not require medical expertise can be performed by AI. However, our results show that, based on the current accuracy, verification by an experienced radiologist is necessary.
CRIS-Team WoS Importer:2020-07-24

Bildgebung in der Mammadiagnostik – Ein Ausblick - Schulz-Wendtland, Rüdiger; Bock, Karin (Gynäkologe, 2020)
Developing new imaging modalities remains a challenge. The latest developments are intelligent innovations building on technologies that have been on the market for decades. One cannot reinvent the wheel, but one can start to improve pre-existing technologies by concentrating on their week points. Fusion technologies are promising, as are applications in artificial intelligence. Any imaging modality needs to prove its reliability and stability, as well as its effectiveness and efficiency. It must also be easy to access. The expected benefit must far outweigh possible disadvantages. And it must be affordable for the health care system. There is no ground-breaking new modality on the horizon as yet—but if anyone has any ideas, please come forward!
CRIS-Team Scopus Importer:2020-04-28
Keywords: Artificial intelligence; Breast ultrasound; Early detection of breast cancer; Efficiency; Mammography

Characterization of the diffusion coefficient of blood - Funck, Carsten; Laun, Frederik Bernd; Wetscherek, Andreas (Magnetic Resonance in Medicine, 2018)
PURPOSE: To characterize the diffusion coefficient of human blood for accurate results in intravoxel incoherent motion imaging. METHODS: Diffusion-weighted MRI of blood samples from 10 healthy volunteers was acquired with a single-shot echo-planar-imaging sequence at body temperature. Effects of gradient profile (monopolar or flow-compensated), diffusion time (40-100 ms), and echo time (60-200 ms) were investigated. RESULTS: Although measured apparent diffusion coefficients of blood were larger for flow-compensated than for monopolar gradients, no dependence of the apparent diffusion coefficient on the diffusion time was found. Large differences between individual samples were observed, with results ranging from 1.26 to 1.66 µm2 /ms for flow-compensated and 0.94 to 1.52 µm2 /ms for monopolar gradients. Statistical analysis indicates correlations of the flow-compensated apparent diffusion coefficient with hematocrit (P = 0.007) and hemoglobin (P = 0.017), but not with mean corpuscular volume (P = 0.64). Results of Monte-Carlo simulations support the experimental observations. CONCLUSIONS: Measured blood apparent diffusion coefficient values depend on hematocrit/hemoglobin concentration and applied gradient profile due to non-Gaussian diffusion. Because in vivo measurement is delicate, an estimation based on blood count results could be an alternative. For intravoxel incoherent motion modeling, the use of a blood self-diffusion constant Db = 1.54 ± 0.12 µm2 /ms for flow-compensated and Db = 1.30 ± 0.18 µm2 /ms for monopolar encoding is suggested. Magn Reson Med 79:2752-2758, 2018. © 2017 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
EVALuna2:36253

Exploring MR regression patterns in rectal cancer during neoadjuvant radiochemotherapy with daily T2- And diffusion-weighted MRI - Bostel, T.; Dreher, C.; Wollschläger, D.; Mayer, A.; König, F.; Bickelhaupt, S.; Schlemmer, H. P.; Huber, P. E.; Sterzing, F.; Bäumer, P.; Debus, J.; Nicolay, N. H. (Radiation Oncology, 2020)
Background: To date, only limited magnetic resonance imaging (MRI) data are available concerning tumor regression during neoadjuvant radiochemotherapy (RCT) of rectal cancer patients, which is a prerequisite for adaptive radiotherapy (RT) concepts. This exploratory study prospectively evaluated daily fractional MRI during neoadjuvant treatment to analyze the predictive value of MR biomarkers for treatment response. Methods: Locally advanced rectal cancer patients were examined with daily MRI during neoadjuvant RCT. Contouring of the tumor volume was performed for each MRI scan by using T2- and diffusion-weighted-imaging (DWI)-sequences. The daily apparent-diffusion coefficient (ADC) was calculated. Volumetric and functional tumor changes during RCT were analyzed and correlated with the pathological response after surgical resection. Results: In total, 171 MRI scans of eight patients were analyzed regarding anatomical and functional dynamics during RCT. Pathological complete response (pCR) could be achieved in four patients, and four patients had a pathological partial response (pPR) following neoadjuvant treatment. T2- and DWI-based volumetry proved to be statistically significant in terms of therapeutic response, and volumetric thresholds at week two and week four during RCT were defined for the prediction of pCR. In contrast, the average tumor ADC values widely overlapped between both response groups during RCT and appeared inadequate to predict treatment response in our patient cohort. Conclusion: This prospective exploratory study supports the hypothesis that MRI may be able to predict pCR of rectal cancers early during neoadjuvant RCT. Our data therefore provide a useful template to tailor future MR-guided adaptive treatment concepts.
CRIS-Team Scopus Importer:2020-07-24
Keywords: Chemoradiotherapy; IGRT; MRI; Oncologic imaging; Pathological response; Rectal cancer

Mammadiagnostik: von der klinischen Diagnostik bis zur künstlichen Intelligenz - Schulz-Wendtland, Rüdiger; Reiser, M. (Radiologe, 2021)
CRIS-Team Scopus Importer:2021-02-12

Radiation dose management systems—requirements and recommendations for users from the ESR EuroSafe Imaging initiative - Loose, Reinhard; Vano, Eliseo; Mildenberger, Peter; Tsapaki, Virginia; Caramella, Davide; Sjöberg, Johan; Paulo, Graciano; Torresin, Alberto; Schindera, Sebastian; Frija, Guy; Damilakis, John (European Radiology, 2020)
Abstract: The European Directive 2013/59/Euratom requires member states of the European Union to ensure justification and optimisation of radiological procedures and store information on patient exposure for analysis and quality assurance. The EuroSafe Imaging campaign of the European Society of Radiology created a working group (WG) on “Dose Management” with the aim to provide European recommendations on the implementation of dose management systems (DMS) in clinical practice. The WG follows Action 4: “Promote dose management systems to establish local, national, and European diagnostic reference levels (DRL)” of the EuroSafe Imaging Call for Action 2018. DMS are designed for medical practitioners, radiographers, medical physics experts (MPE) and other health professionals involved in imaging to support their tasks and duties of radiation protection in accordance with local and national requirements. The WG analysed requirements and critical points when installing a DMS and classified the individual functions at different performance levels. Key Points: • DMS are very helpful software tools for monitoring patient exposure, optimisation, compliance with DRLs and quality assurance. • DMS can help to fulfil dosimetric aspects of the European Directive 2013/59/Euratom. • The EuroSafe WG analyses DMS requirements and gives recommendations for users.
CRIS-Team Scopus Importer:2020-10-02
Keywords: Dose management systems; Optimisation; Quality assurance; Radiation protection

S2k guidelines for the therapy of pathological scars (hypertrophic scars and keloids) – Update 2020 - Nast, Alexander; Gauglitz, Gerd; Lorenz, Kerstin; Metelmann, Hans-Robert; Paasch, Uwe; Strnad, Vratislav; Weidmann, Michael; Werner, Ricardo Niklas; Bauerschmitz, Jürgen (Journal der Deutschen Dermatologischen Gesellschaft, 2020)
CRIS-Team Scopus Importer:2020-10-16

Solving the preoperative breast MRI conundrum: design and protocol of the MIPA study - Sardanelli, Francesco; Trimboli, Rubina M.; Houssami, Nehmat; Gilbert, Fiona J.; Helbich, Thomas H.; Alvarez Benito, Marina; Balleyguier, Corinne; Bazzocchi, Massimo; Bult, Peter; Calabrese, Massimo; Camps Herrero, Julia; Cartia, Francesco; et al. (European Radiology, 2020)
Despite its high diagnostic performance, the use of breast MRI in the preoperative setting is controversial. It has the potential for personalized surgical management in breast cancer patients, but two of three randomized controlled trials did not show results in favor of its introduction for assessing the disease extent before surgery. Meta-analyses showed a higher mastectomy rate in women undergoing preoperative MRI compared to those who do not. Nevertheless, preoperative breast MRI is increasingly used and a survey from the American Society of Breast Surgeons showed that 41% of respondents ask for it in daily practice. In this context, a large-scale observational multicenter international prospective analysis (MIPA study) was proposed under the guidance of the European Network for the Assessment of Imaging in Medicine (EuroAIM). The aims were (1) to prospectively and systematically collect data on consecutive women with a newly diagnosed breast cancer, not candidates for neoadjuvant therapy, who are offered or not offered breast MRI before surgery according to local practice; (2) to compare these two groups in terms of surgical and clinical endpoints, adjusting for covariates. The underlying hypotheses are that MRI does not cause additional mastectomies compared to conventional imaging, while reducing the reoperation rate in all or in subgroups of patients. Ninety-six centers applied to a web-based call; 36 were initially selected based on volume and quality standards; 27 were active for enrollment. On November 2018, the target of 7000 enrolled patients was reached. The MIPA study is presently at the analytic phase. Key Points center dot Breast MRI has a high diagnostic performance but its utility in the preoperative setting is controversial. center dot A large-scale observational multicenter prospective study was launched to compare women receiving with those not receiving preoperative MRI. center dot Twenty-seven centers enrolled more than 7000 patients. The study is presently at the analytic phase.
CRIS-Team WoS Importer:2020-05-15

Ultra-High-b-Value Kurtosis Imaging for Noninvasive Tissue Characterization of Ovarian Lesions - Mokry, Theresa; Mlynarska-Bujny, Anna; Kuder, Tristan Anselm; Hasse, Felix Christian; Hog, Robert; Wallwiener, Markus; Dinkic, Christine; Brucker, Janina; Sinn, Peter; Gnirs, Regula; Kauczor, Hans Ulrich; Schlemmer, Heinz Peter; et al. (Radiology, 2020)
Background MRI with contrast material enhancement is the imaging modality of choice to evaluate sonographically indeterminate adnexal masses. The role of diffusion-weighted MRI, however, remains controversial. Purpose To evaluate the diagnostic performance of ultra-high-b-value diffusion kurtosis MRI in discriminating benign and malignant ovarian lesions. Materials and Methods This prospective cohort study evaluated consecutive women with sonographically indeterminate adnexal masses between November 2016 and December 2018. MRI at 3.0 T was performed, including diffusion-weighted MRI (b values of 0-2000 sec/mm2). Lesions were segmented on b of 1500 sec/mm2 by two readers in consensus and an additional independent reader by using full-lesion segmentations on a single transversal slice. Apparent diffusion coefficient (ADC) calculation and kurtosis fitting were performed. Differences in ADC, kurtosis-derived ADC (Dapp), and apparent kurtosis coefficient (Kapp) between malignant and benign lesions were assessed by using a logistic mixed model. Area under the receiver operating characteristic curve (AUC) for ADC, Dapp, and Kapp to discriminate malignant from benign lesions was calculated, as was specificity at a sensitivity level of 100%. Results from two independent reads were compared. Histopathologic analysis served as the reference standard. Results A total of 79 ovarian lesions in 58 women (mean age ± standard deviation, 48 years ± 14) were evaluated. Sixty-two (78%) lesions showed benign and 17 (22%) lesions showed malignant histologic findings. ADC and Dapp were lower and Kapp was higher in malignant lesions: median ADC, Dapp, and Kapp were 0.74 µm2/msec (range, 0.52-1.44 µm2/msec), 0.98 µm2/msec (range, 0.63-2.12 µm2/msec), and 1.01 (range, 0.69-1.30) for malignant lesions, and 1.13 µm2/msec (range, 0.35-2.63 µm2/msec), 1.45 µm2/msec (range, 0.44-3.34 µm2/msec), and 0.65 (range, 0.44-1.43) for benign lesions (P values of .01, .02, < .001, respectively). AUC for Kapp of 0.85 (95% confidence interval: 0.77, 0.94) was higher than was AUC from ADC of 0.78 (95% confidence interval: 0.67, 0.89; P = .047). Conclusion Diffusion-weighted MRI by using quantitative kurtosis variables is superior to apparent diffusion coefficient values in discriminating benign and malignant ovarian lesions and might be of future help in clinical practice, especially in patients with contraindication to contrast media application. © RSNA, 2020 Online supplemental material is available for this article.
CRIS-Team Scopus Importer:2020-07-31